Jupiter – Largest Planet – 4.5 Billion years

Jupiter: Our Solar System’s Largest Planet

This new Hubble Space Telescope view of Jupiter, taken on June 27, 2019, reveals the giant planet’s trademark Great Red Spot, and a more intense color palette in the clouds swirling in Jupiter’s turbulent atmosphere than seen in previous years. Hubble’s Wide Field Camera 3 observed Jupiter when the planet was 400 million miles (640 million kilometers) from Earth, when Jupiter was near “opposition,” or almost directly opposite the sun in the sky.

(Image: © NASA, ESA, A. Simon (Goddard Space Flight Center) and M.H. Wong (University of California, Berkeley))

Jupiter is the largest planet in the solar system. Fittingly, it was named after the king of the gods in Roman mythology. In a similar manner, the ancient Greeks named the planet after Zeus, the king of the Greek pantheon.

Jupiter helped revolutionize the way we saw the universe and ourselves in 1610, when Galileo discovered Jupiter’s four large moons — Io, Europa, Ganymede and Callisto, now known as the Galilean moons. This was the first time that celestial bodies were seen circling an object other than Earth, and gave major support to the Copernican view that Earth was not the center of the universe.

NASA: https://solarsystem.nasa.gov/planets/jupiter/overview/

Physical characteristics

Jupiter is more than twice as massive as all the other planets combined. If the enormous planet was about 80 times more massive, it would have actually become a star instead of a planet. Jupiter’s immense volume could hold more than 1,300 Earths. That means that if Jupiter were the size of a basketball, Earth would be the size of a grape.

Jupiter has a dense core of uncertain composition, surrounded by a helium-rich layer of fluid metallic hydrogen that extends out to 80% to 90% of the diameter of the planet.

Jupiter’s atmosphere resembles that of the sun, made up mostly of hydrogen and helium. The colorful light and dark bands that surround Jupiter are created by strong east-west winds in the planet’s upper atmosphere traveling more than 335 mph (539 km/h). The white clouds in the light zones are made of crystals of frozen ammonia, while darker clouds made of other chemicals are found in the dark belts. At the deepest visible levels are blue clouds. Far from being static, the stripes of clouds change over time. Inside the atmosphere, diamond rain may fill the skies.

The most extraordinary feature on Jupiter is the Great Red Spot, a giant hurricane-like storm that’s lasted more than 300 years. At its widest, the Great Red Spot is about twice the size of Earth, and its edge spins counterclockwise around its center at speeds of about 270 to 425 mph (430 to 680 km/h). The color of the storm, which usually varies from brick red to slightly brown, may come from small amounts of sulfur and phosphorus in the ammonia crystals in Jupiter’s clouds. The spot has been shrinking for quite some time, although the rate may be slowing in recent years.

Jupiter’s gargantuan magnetic field is the strongest of all the planets in the solar system at nearly 20,000 times the strength of Earth’s. It traps electrically charged particles in an intense belt of electrons and other electrically charged particles that regularly blasts the planet’s moons and rings with radiation more than 1,000 times the lethal level for a human, enough to damage even heavily shielded spacecraft, such as NASA’s Galileo probe. The magnetosphere of Jupiter swells out some 600,000 to 2 million miles (1 million to 3 million kilometers) toward the sun and tapers to a tail extending more than 600 million miles (1 billion km) behind the massive planet.

Jupiter also spins faster than any other planet, taking a little under 10 hours to complete a turn on its axis, compared with 24 hours for Earth. This rapid spin makes Jupiter bulge at the equator and flatten at the poles.

Jupiter broadcasts radio waves strong enough to detect on Earth. These come in two forms — strong bursts that occur when Io, the closest of Jupiter’s large moons, passes through certain regions of Jupiter’s magnetic field, and continuous radiation from Jupiter’s surface and high-energy particles in its radiation belts.

Orbit & rotation

Average distance from the sun: 483,682,810 miles (778,412,020 km). By comparison: 5.203 times that of Earth.

Perihelion (closest approach to the sun): 460,276,100 miles (740,742,600 km). By comparison: 5.036 times that of Earth.

Aphelion (farthest distance from the sun): 507,089,500 miles (816,081,400 km). By comparison: 5.366 times that of Earth.

From time to time, the small round black shadows cast by Jupiter’s four Galilean moons become visible in amateur telescopes as they cross (or transit) the planet’s disk. Here’s two of those shadows on Jupiter at the same time, Europa’s and Ganymede’s.  (Image credit: Starry Night software)

Jupiter’s moons

With four large moons and many smaller moons in orbit around it, Jupiter by itself forms a kind of miniature solar system.

Jupiter has 79 known moons, which are mostly named after the paramours of Roman gods. The four largest moons of Jupiter, called Io, Europa, Ganymede and Callisto, were discovered by Galileo Galilei.

Ganymede is the largest moon in our solar system, and is larger than Mercury and Pluto. It is also the only moon known to have its own magnetic field. The moon has at least one ocean between layers of ice, although it may contain several layers of both ice and water, stacked on top of one another. Ganymede will be the main target of the European Jupiter Icy Moons Explorer (JUICE) spacecraft that’s scheduled to launch in 2022 and arrive at Jupiter’s system in 2030.

Io is the most volcanically active body in our solar system. The sulfur its volcanoes spew gives Io a blotted yellow-orange appearance that looks kind of like a pepperoni pizza. As Io orbits Jupiter, the planet’s immense gravity causes “tides” in Io’s solid surface that rise 300 feet (100 meters) high and generate enough heat for volcanic activity.

The frozen crust of Europa is made up mostly of water ice, and it may hide a liquid ocean that contains twice as much water as Earth does. Some of this liquid spouts from the surface in newly spotted sporadic plumes at Europa’s southern pole. NASA’s Europa Clipper mission, a planned spacecraft that would launch in the 2020s to explore the icy moon, is now in phase B (the design stage). It would perform 40 to 45 flybys to examine the habitability of the moon.

Callisto has the lowest reflectivity, or albedo, of the four Galilean moons. This suggests that its surface may be composed of dark, colorless rock.

Jupiter’s rings

Jupiter’s three rings came as a surprise when NASA’s Voyager 1 spacecraft discovered them around the planet’s equator in 1979. Each are much fainter than Saturn’s rings.

The main ring is flattened. It is about 20 miles (30 km) thick and more than 4,000 miles (6,400 km) wide.

The inner cloud-like ring, called the halo, is about 12,000 miles (20,000 km) thick. The halo is caused by electromagnetic forces that push grains away from the plane of the main ring. This structure extends halfway from the main ring down to the planet’s cloud tops and expands. Both the main ring and halo are composed of small, dark particles of dust.

The third ring, known as the gossamer ring because of its transparency, is actually three rings of microscopic debris from three of Jupiter’s moons, Amalthea, Thebe and Adrastea. It is probably made up of dust particles less than 10 microns in diameter, about the same size of the particles found in cigarette smoke, and extends to an outer edge of about 80,000 miles (129,000 km) from the center of the planet and inward to about 18,600 miles (30,000 km).

Ripples in the rings of both Jupiter and Saturn may be signs of impacts from comets and asteroids.

Zoomed-in version of Juno’s unprecedented photo of Jupiter’s ring system, with the outlines of the Orion constellation mapped out.  (Image credit: NASA/JPL-Caltech/SwRI)

Research & exploration

Seven missions have flown by Jupiter — Pioneer 10, Pioneer 11, Voyager 1, Voyager 2, Ulysses, Cassini and New Horizons. Two missions — NASA’s Galileo and Juno missions — have orbited the planet. Two future missions are planned to study Jupiter’s moons: NASA’s Europa Clipper (which would launch in the 2020s) and the European Space Agency’s Jupiter Icy Moons Explorer (JUICE) that will launch in 2022 and arrive at Jupiter’s system in 2030 to study Ganymede, Callisto and Europa.

Pioneer 10 revealed how dangerous Jupiter’s radiation belt is, while Pioneer 11 provided data on the Great Red Spot and close-up pictures of Jupiter’s polar regions. Voyager 1 and 2 helped astronomers create the first detailed maps of the Galilean satellites, discovered Jupiter’s rings, revealed sulfur volcanoes on Io and detected lightning in Jupiter’s clouds. Ulysses discovered the solar wind has a much greater impact on Jupiter’s magnetosphere than what was previously suggested. New Horizons took close-up pictures of Jupiter and its largest moons.

In 1995, Galileo sent a probe plunging toward Jupiter, making the first direct measurements of the planet’s atmosphere and measuring the amount of water and other chemicals there. When Galileo ran low on fuel, the craft was intentionally crashed into Jupiter to avoid any risk of it slamming into and contaminating Europa, which might have an ocean below its surface capable of supporting life.

Juno is the only mission at Jupiter at the moment. Juno studies Jupiter from a polar orbit to figure out how it and the rest of the solar system formed, which could shed light on how alien planetary systems might have developed. One of its key findings so far was discovering that Jupiter’s core may be larger than what scientists expected.

How Jupiter shaped our solar system

As the most massive body in the solar system after the sun, the pull of Jupiter’s gravity has helped shape the fate of our system. Jupiter’s gravity is likely responsible for  violently hurling Neptune and Uranus outward. Jupiter, along with Saturn, may have slung a barrage of debris toward the inner planets early in the system’s history, although some scientists debate how much of a role each planet played in moving the asteroids around. Jupiter may also help keep asteroids from bombarding Earth, and recent events have shown that Jupiter can absorb some pretty significant impacts. Observations by amateurs have shown that Jupiter receives a few major impacts per decade, far more than what was predicted when Comet Shoemaker Levy-9 crashed into the planet in 1994.

Currently, Jupiter’s gravitational field influences numerous asteroids that have clustered into the regions preceding and following Jupiter in its orbit around the sun. These are known as the Trojan asteroids, after three large asteroids there, Agamemnon, Achilles and Hector. Their names were drawn from the Iliad, Homer’s epic about the Trojan War.

Could there be life on Jupiter?

Jupiter’s atmosphere grows warmer with depth, reaching room temperature, or 70 degrees F (21 degrees C), at an altitude where the atmospheric pressure is about 10 times as great as it is on Earth. Scientists suspect that if Jupiter has any form of life, it might dwell at this level, and it would have to be airborne. However, researchers have found no evidence for life on Jupiter.

10 Need-to-Know Things About Jupiter

1

THE GRANDEST PLANET

Eleven Earths could fit across Jupiter’s equator. If Earth were the size of a grape, Jupiter would be the size of a basketball.

2

FIFTH PLANET FROM OUR STAR

Jupiter orbits about 484 million miles (778 million kilometers) or 5.2 Astronomical Units (AU) from our Sun (Earth is one AU from the Sun).

3

SHORT DAY/LONG YEAR

Jupiter rotates once about every 10 hours (a Jovian day), but takes about 12 Earth years to complete one orbit of the Sun (a Jovian year).

JUPITER AND IO

4

WHAT’S INSIDE

Jupiter is a gas giant and so lacks an Earth-like surface. If it has a solid inner core at all, it’s likely only about the size of Earth.

5

MASSIVE WORLD, LIGHT ELEMENTS

Jupiter’s atmosphere is made up mostly of hydrogen (H₂) and helium (He).

6

WORLDS GALORE

Jupiter has more than 75 moons.

7

RINGED WORLD

In 1979 the Voyager mission discovered Jupiter’s faint ring system. All four giant planets in our solar system have ring systems.

8

EXPLORING JUPITER

Nine spacecraft have visited Jupiter. Seven flew by and two have orbited the gas giant. Juno, the most recent, arrived at Jupiter in 2016.

9

INGREDIENTS FOR LIFE?

Jupiter cannot support life as we know it. But some of Jupiter’s moons have oceans beneath their crusts that might support life.

10

SUPER STORM

Jupiter’s Great Red Spot is a gigantic storm that’s about twice the size of Earth and has raged for over a century.

Sassanid (Neo-Persian) Empire 224-651 AD

The Sasanian Empire , also known as the Sassanian, Sasanid, Sassanid or Neo-Persian Empire was the last period of the Persian Empire (Iran) before the rise of Islam, named after the House of Sasan who ruled from 224 to 651 AD.T

he Sasanian Empire, which succeeded the Parthian Empire, was recognised as one of the leading world powers alongside its neighbouring arch-rival the Roman-Byzantine Empire, for a period of more than 400 years.

Nero 37-68 AD

Perhaps the most infamous of Rome’s emperors, Nero Claudius Caesar (37-68 A.D.) ruled Rome from 54 A.D. until his death by suicide 14 years later. He is best known for his debaucheries, political murders, persecution of Christians and a passion for music that led to the probably apocryphal rumor that Nero “fiddled” while Rome burned during the great fire of 64 A.D.

Nero’s Murderous Path to Power

Born Lucius Domitius Ahenobarbus, Nero took his familiar name when he was adopted at age 13 by his great-uncle, the emperor Claudius (his father, Gnaeus Domitius Ahenobarbus, had died when the future emperor was only 2). Nero’s mother, Agrippina the Younger, had married Claudius after arranging the death of her second husband and was the driving force behind her son’s adoption. She arranged for Nero to wed Claudius’ daughter Octavia in 53, further sidelining the emperor’s son Britannicus. Upon Claudius’ sudden death in 54—classical sources suggest Agrippina fed him poisoned mushrooms—the 17-year-old Nero ascended the throne.

Did you know? Although it’s unknown whether Nero sang and strummed his lyre while Rome burned in 64 A.D., he certainly didn’t play a fiddle: bowed string instruments wouldn’t appear in Europe for another 800 years.

In his first five years as emperor, Nero gained a reputation for political generosity, promoting power-sharing with the Senate and ending closed-door political trials, though he generally pursued his own passions and left the ruling up to three key advisers—the Stoic philosopher Seneca, the prefect Burrus and ultimately Agrippina.

Eventually Seneca encouraged Nero to step out from his domineering mother’s shadow. She turned against him, promoting her stepson Britannicus as the true heir to the throne and protesting Nero’s affair with his friend’s wife Poppaea Sabina. But Nero had learned his mother’s lessons well: Brittanicus soon died under dubious circumstances, and in 59, after a failed plot to drown her in a collapsible boat, Nero had Agrippina stabbed to death in her villa. The empress Octavia was exiled and executed, and in 62 Nero and Poppaea were married. Three years later, in what the Roman historian Tacitus described as “a casual outburst of rage,” Nero killed Poppea with a single kick to her belly.

Nero: The Artist and the Fire

Following his mother’s death, Nero gave himself fully to his longstanding artistic and aesthetic passions. At private events beginning in 59, he sang and performed on the lyre and encouraged members of the upper classes to take dancing lessons. He ordered public games to be held every five years in Rome and trained as an athlete himself, competing as a charioteer. His most lasting artistic legacy, though, was his re-creation of Rome following the fire that destroyed most of the city.

Early in the morning of June 19, 64 a blaze broke out in the shops around the Circus Maximus and quickly spread throughout the city. Over the next nine days, three of Rome’s 14 districts were destroyed and an additional seven were severely damaged. Several classical sources place Nero on the roof of his palace during the fire, dressed in stage garb and singing from the Greek epic “The Sack of Ilium.” Rumors quickly circulated that the emperor had started the fire to clear land for an expanded palace complex on the Palatine Hill.

Whatever responsibility he actually bore for the disaster, Nero deflected attention by blaming members of the fledgling Christian religion for the fire. He ordered all manner of creative and brutal persecutions: Some were condemned to be dressed in animal skins and torn apart by dogs, while others were burned to death in nighttime pyres that provided light for the emperor’s garden parties.

Nero exhausted the Roman treasury rebuilding the city around his 100-acre Domus Aurea (“Golden House”) palace complex. At its center he commissioned a 100-foot-tall bronze statue of himself, the Colossus Neronis.

Nero’s Decline and Fall

By the final years of his Nero’s rule, the Roman Empire was under great strain. Reconstruction costs in Rome, revolts in Britain and Judea, conflicts with Parthia and rebuilding expenses in the capital forced him to devalue the imperial currency, lowering the silver content of the denarius by 10 percent. In 65 a high-level conspiracy to assassinate the emperor emerged, leading Nero to order the deaths of a prefect and several senators and officers. The emperor’s old advisor Seneca was caught up in the affair and forced to commit suicide.

With things falling apart at home, Nero took an extended tour of Greece, where he gave himself to music and theatrical performance, drove a chariot in the Olympic games, announced pro-Hellenic political reforms and launched an expensive and futile project to dig a canal across the Isthmus of Corinth.

Upon his return to Rome in 68, Nero failed to respond decisively to a revolt in Gaul, prompting further unrest in Africa and in Spain, where the governor Galba declared himself legate of the Senate and Roman People. Soon the Praetorian Guard declared allegiance to Galba, and the Senate followed suit, declaring Nero an enemy of the people.

Nero attempted to flee, but upon learning that his arrest and execution were imminent, he took his own life. Fifty years later, the historian Suetonius reported Nero’s final lament: “What an artist dies in me!”

Nero’s Legacy

In the centuries followed his reign, the name Nero would become a byword for debauchery, misrule and anti-Christian persecution. In the short term, his demise marked the end of the Julio-Claudian Dynasty, which had ruled Rome since 27 B.C. It would be 30 years before Rome had another emperor, Trajan, who would rule as long as Nero had. Nero’s death was followed by the chaotic “Year of the Four Emperors,” which the Roman historian Tacitus described as “a period rich in disasters … even in peace full of horrors.” So while many of Nero’s contemporaries celebrated his death, others looked back on the pomp and celebrations of his reign with nostalgia.

Caligula 37-41 AD

The third of Rome’s emperors, Caligula (formally known as Gaius) achieved feats of waste and carnage during his four-year reign (A.D. 37-41) unmatched even by his infamous nephew Nero. The son of a great military leader, he escaped family intrigues to take the throne, but his personal and fiscal excesses led him to be the first Roman emperor to be assassinated.

Caligula’s Early Life

Gaius Julius Caesar Germanicus was born in 12 A.D., the third son of the renowned Roman general Germanicus and his wife, Agrippina the Elder. During his childhood, his family lived at his father’s posting on the Rhine, where the general’s troops gave the future emperor his nickname “Caligula,” meaning “little boot,” in reference to the miniature uniform in which his parents dressed him.

Did you know? Though known for his harsh treatment of others, the infamous Roman emperor Caligula lavished attention upon his horse Incitatus, giving the animal his own house with a marble stall and ivory manger. As an expression of his absolute power, Caligula planned to appoint the horse to the high office of consul, but he was assassinated before he could do so.

After Germanicus died in 17 A.D., Caligula’s family fell from favor in the eyes of the emperor Tiberius and the powerful Praetorian guardsman Sejanus, who saw the elder sons of the popular general as political rivals. Caligula’s mother and brothers were accused of treason, and all died in prison or exile. Caligula’s grandmother Antonia managed to shield him from these intrigues until Sejunus’ death in 31. The next year, Caligula moved in with the aging Tiberius, who gleefully indulged his great-nephew’s worst habits, commenting that he was “nursing a viper in Rome’s bosom.”

Tiberius adopted Caligula and made him and his cousin Gemellus equal heirs to the empire. When the emperor died in 37, Caligula’s Praetorian ally Marco arranged for Caligula to be proclaimed sole emperor. A year later, Caligula would order both Marco and Gemellus put to death.

The Emperor Caligula

Caligula was not quite 25 years old when he took power in 37 A.D. At first, his succession was welcomed in Rome: He announced political reforms and recalled all exiles. But in October of 37, a serious illness unhinged Caligula, leading him to spend the remainder of his reign exploring the worst aspects of his nature.

Caligula lavished money on building projects, from the practical (aqueducts and harbors) to the cultural (theaters and temples) to the downright bizarre (requisitioning hundreds of Roman merchant ships to construct a 2-mile floating bridge across the Bay of Bauli so he could spend two days galloping back and forth across it). In 39 and 40 he led military campaigns to the Rhine and the English Channel, where he eschewed battles for theatrical displays, commanding his troops to “plunder the sea” by gathering shells in their helmets).

His relationships with other individuals were turbulent as well. His biographer Suetonius quotes his oft-repeated phrase, “Remember that I have the right to do anything to anybody.” He tormented high-ranking senators by making them run for miles in front of his chariot. He had brazen affairs with the wives of his allies and was rumored to have incestuous relationships with his sisters.

Caligula was tall, pale and so hairy that he made it a capital offense to mention a goat in his presence. He worked to accentuate his natural ugliness by practicing terrifying facial expressions in a mirror. But he literally wallowed in luxury, allegedly rolling around in piles of money and drinking precious pearls dissolved in vinegar. He continued his childhood games of dress-up, donning strange clothing, women’s shoes and lavish accessories and wigs—eager, according to his biographer Cassius Dio, “to appear to be anything rather than a human being and an emperor.”

Caligula’s Downfall

Caligula’s profligacy was draining the Roman treasury faster than he could replenish it through taxes and extortion. A conspiracy formed between the Praetorian Guard, the Senate and the equestrian order, and in late January of 41 A.D. Caligula was stabbed to death, along with his wife and daughter, by officers of the Praetorian Guard led by Cassius Chaerea. Thus, Cassius Dio notes, Caligula “learned by actual experience that he was not a god.”

The Senate attempted to use the disastrous end of Caligula’s reign as a pretext to reestablish the Roman Republic, but Claudius, the heir designate, took the throne after gaining the support of the Praetorian Guard. The Julio-Claudian dynasty would remain secure for another 17 years, until Nero’s suicide in 68.

Mark Antony 83–30 B.C.

The Roman politician and general Mark Antony (83–30 B.C.) was an ally of Julius Caesar and the main rival of his successor Octavian (later Augustus). With those two men he was integral to Rome’s transition from republic to empire. His romantic and political alliance with the Egyptian queen Cleopatra was his ultimate undoing, and centuries later provided inspiration for artists from Shakespeare to Cecil B. DeMille.

Mark Antony: Early Life and Alliance with Julius Caesar

Marcus Antonius was born in Rome in 83 B.C., the son of an ineffective praetor (military commander) and grandson of a noted consul and orator, both of whom shared his given name. After a largely misspent youth, he was sent east as a cavalry officer, where he won important victories in Palestine and Egypt. In 54 B.C. he went to Gaul to join his mother’s cousin Julius Caesar as a staff officer. In 49 B.C. he was elected a tribune and served as a staunch defender of Caesar against his rivals in the Senate.

Did you know? Although Mark Antony died fighting Octavian’s efforts to become Rome’s sole dynastic monarch, three of the first five Roman emperors—Caligula, Claudius and Nero—were Antony’s direct descendants.

During Caesar’s first yearlong dictatorship, Antony was his second-in-command. By 48 B.C. he was in Greece, supporting Caesar’s left wing at the Battle of Pharsalus. A year later, Antony’s violent expulsion from the Senate by anti-Caesar factions gave Caesar’s legion a rallying point as they crossed the Rubicon River, igniting the Republican Civil War. When Caesar assumed his fifth and final consulship in 44 B.C., Antony was his co-consul.

As the Ides of March approached, Antony heard rumors of a plot against Caesar but was unable to warn him in time. Antony fled Rome dressed as a slave but soon returned to protect his friend’s legacy from the senators who had conspired against him. He took charge of Caesar’s will and papers and gave a stirring eulogy for the fallen leader.

Mark Antony and Octavian

In his will Caesar had bequeathed his wealth and title to his posthumously adopted son Octavian. Antony was reluctant to hand his old friend’s legacy to a 17-year-old, and quickly became a rival to the future emperor. In 43 B.C. their armies first clashed. Antony was driven back at Mutina and Forum Gallorum, but had proved a formidable enough leader that Octavian preferred to ally with him.

Along with their lesser rival Lepidus, Octavian and Antony formed the Second Triumvirate, splitting Rome’s provinces between them: Octavian would rule the West, Antony the East and Lepidus Africa. Within a year, Antony defeated Caesar’s assassins Brutus and Antonius at Phillipi, eliminating the two remaining leaders of the Republican cause in a battle that established his reputation as a general.

Mark Antony and Cleopatra

In 41 B.C. Antony began an affair with the Egyptian queen Cleopatra, who had been Caesar’s lover in the last years of his life. The queen gave birth to twins, Alexander Helios and Cleopatra Selene, but Antony was forced to return to Rome to deal with the aftermath of his wife and brother-in-law’s failed rebellion against Octavian. The Senate pushed for conciliation between the triumvirs, pressing the recently widowed Antony to marry Octavian’s sister Octavia Minor in 40 B.C.

In 37 B.C. the Triumvirate was renewed. Antony returned to Cleopatra and fathered a son, Ptolemy Philadelphus. The lovers grew more public in their relationship, participating in deification ceremonies where they took the roles of the Greco-Egyptian gods Dionysus-Osiris and Venus-Isis. More provocatively, they paraded their three children and Caesarion (Cleopatra’s son by Julius Ceasar) in costumes as legitimate royal heirs, flaunting Roman law’s refusal to acknowledge marriage with outsiders. Politically, Antony grew more and more entwined with the Egyptian kingdom, having turned to Cleopatra for help following his failed expedition against the Parthians in 36 B.C.

Meanwhile Octavian grew in strength, eliminating Lepidus from the triumvirate on a pretext of rebellion. In 32 B.C. Antony divorced Octavia. In retaliation, Octavian declared war, not on Antony but on Cleopatra. The fighting occurred in western Greece, where Antony had superior numbers but fell time and again to the brilliant naval attacks of Octavian’s general Agrippa. After their combined forces were defeated at Actium, Antony and Cleopatra’s remaining ships made a desperate flight back to Egypt, pursued by Agrippa and Octavian.

As Octavian entered Alexandria, both Antony and Cleopatra resolved to commit suicide. Antony, thinking his lover already dead, stabbed himself with a sword but was then brought to die in Cleopatra’s arms. Cleopatra was captured but managed to kill herself via a poisonous snakebite. After Antony’s death his honors were all revoked, his statues removed. Cicero, Antony’s great rival in the senate, decreed that no one in the dead general’s family would ever bear the name Mark Antony again. Octavian was now emperor in all but name. Three years later he was granted a new honorific, Augustus, and ruled Rome for the next four decades.