Who Was Marcus Agrippa? The Roman General Behind Emperor Augustus

Marcus Vipsanius Agrippa was a Roman general and official whose role in the Roman Empire’s foundation was perhaps even more significant than Augustus himself.

Jun 10, 2021By Vedran Bileta, MA in Late Antique, Byzantine, and Early Modern History, BA in History
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Bust of Marcus Vipsanius Agrippa, 25-24 BCE; with the Pantheon in Rome, built under Agrippa


History remembers great leaders. We know of Alexander the Great, Queen Elizabeth II, Napoleon, Abraham Lincoln. However, each of those rulers could not achieve greatness without the people who worked out of the spotlight: generals and advisors who carried out their orders and made sure things got done. For Augustus, the man who created the Roman Empire, that was Marcus Vipsanius Agrippa (63–12 BCE). Agrippa was not only the first Roman emperor’s closest friend and companion. He was also a competent general, admiral, politician, architect, and administrator. He did all that, never asking for credit and rejecting accolades, remaining focused solely on his mission – to lay the foundations for one of the greatest empires the world has ever seen. 


Marcus Agrippa’s Early years

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Bust of Marcus Vipsanius Agrippa, 25-24 BCE, Louvre Museum, Paris


Agrippa’s origin story is quite unusual for someone who would become a founding pillar of the Roman Empire. Marcus Vipsanius Agrippa was born in 64/63 BCE into a humble (but not poor) plebeian family, somewhere in the Italian countryside. The gens Vipsania was an obscure one, appearing only in the late Republic. Agrippa was eager to cast it aside once he started climbing towards the top of the Roman hierarchical pyramid. Agrippa was the same age as Octavian (the future emperor Augustus), and the two boys were educated together with Julius Caesar’s approval. They did not know it yet, but those early years laid the foundation for a life-long friendship between Agrippa and Octavian, which would forever change Rome’s history.


Octavian’s great-uncle Julius Caesar recognized young Agrippa’s potential, taking the young man to Spain to participate in a campaign against the forces led by Pompey’s son. In 45 BCE, Marcus Agrippa fought in the pivotal battle of Munda, which made Caesar the undisputed master of Rome. Following the battle, Caesar sent Agrippa and Octavian to complete their education at an academy in Apollonia, in Illyria. 


Four months later, Agrippa’s and Octavian’s world changed forever. On March 15th 44 BCE (The Ides of March), Julius Caesar was assassinated in Rome. Disregarding his family’s advice not to meddle in political affairs, Octavian, accompanied by Agrippa and a small retinue, sailed to Italy, where he learned that Caesar had adopted him as his son.


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Numismatic portraits of Mark Antony, Octavian, and Lepidus, 39 BCE, The British Museum, London

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The 19-year-old boy was not content to hang out in his villa and allow others to take all the glory. Instead, Octavian plunged headfirst into the political maelstrom with trusty Marcus Agrippa as his right-hand man. And he was going to need Agrippa’s help. By accepting Caesar’s will, Octavian became not only the enemy of Caesar’s murderers but also the rival of Mark Antony, one of Julius Caesar’s best generals, who hoped to fill the power vacuum. With Agrippa’s help and his grand-uncle’s inheritance, Octavian gained support of Caesar’s veterans and loyalists. He also got the backing of the Senate, who considered Antony a greater danger of the two. 


However, the Senate’s strategy backfired as after Antony was defeated in 43 BCE, he formed an alliance with Octavian and Aemilius Lepidus, known as the Second Triumvirate. The Triumvirate’s official mission was to restore the Roman Republic, but the result of its failure would be the establishment of the Empire. 


The General And Admiral

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Coin showing Agrippa, with the sea-god Neptune on reverse, 36 BCE, The British Museum, London


When they met in 43 BCE, the triumvirs agreed to divide the territory under their faction’s control, and deal with Caesar’s murderers who held command over Eastern Mediterranean. Their first act was to remove the ringleaders. In 42 BCE, the triumvirs defeated Brutus and Cassius Longinus at Philippi, and Agrippa likely played an important role in the battle. Phillipi marked the highpoint of the Triumvirate, its members becoming masters of the Republic. Only Sicily remained out of their grasp. The island was held by Sextus Pompey, the last surviving son of Pompey the Great


In 40 BCE, when Sextus’s navy attacked Italy, it was Agrippa who repelled the attack, and forced the enemy to withdraw. In 38, after preventing another conflict between Augustus and Antony BCE Agrippa was sent westwards, as a governor of Transalpine Gaul.


It was in Gaul that Agrippa proved himself a competent commander in his own right. In the same year he crushed a local revolt, and then moved north, to the Rhine, where he fought Germanic tribes. He even became the second Roman general after Caesar to cross the Rhine. 


When in 37 BCE he was summoned back to Rome, Agrippa refused the triumph, not wishing to upstage his friend Octavian. But he was not left without a reward. Still in his early 20s, Agrippa was Octavian’s personal choice for the consulship, the Republic’s highest office. Marcus Agrippa was well below the usual age of 42, and this appointment went against all rules and traditions. Agrippa, however, would soon justify his position. When Sextus Pompey’s navy renewed its attacks, disrupting grain shipments to Rome, Marcus Agrippa was tasked with eliminating the threat.  


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Roman bireme at the battle of Actium, relief from the Temple of Fortuna Primigenia at Praeneste, last third of the 1st century BCE, Vatican Museums, Vatican City, via Wikimedia


By now, it was clear that Octavian was not a talented military commander, and that he depended on Agrippa to do the fighting. And Agrippa delivered. After initial setbacks, Agrippa constructed a hidden harbor on a lake near Naples, which he named Portus Julius, after Octavian (Octavian was using his family name since adoption). There, Agrippa built a fleet and upgraded the ships with several technical innovations. One of them was the harpax – a large ship-mounted ballista that could launch multi-pronged grappling hooks at the enemy vessel, winching it alongside for boarding. Using this technique and his trained crew of sailors and marines, Agrippa demolished Sextus’ fleet, losing only three ships while destroying 28 enemy vessels. The defeat of Sextus caused grain prices in Rome to plummet, and Octavian’s popularity skyrocketed. For his achievement, Agrippa was rewarded with a corona rostrata – an award never given before or after. 


Following the battle, Octavian dismissed Lepidus as a triumvir and became the Western Mediterranean’s sole ruler. The stage was now set for a conflict with Mark Antony. In 32 BCE, Octavian officially declared war on Antony and his mistress Cleopatra. A year later, two Roman fleets met in a battle of Actium, off the Greek coast. Once again, Agrippa’s leadership and skill won the day. Actium was the last battle of the Roman Republic. Both Mark Antony and Cleopatra were soon dead, and Octavian became an undisputed master of Rome. 


Building Augustus’ Empire

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Bust of Agrippa, second half of the 1st century CE, The Uffizi, Florence; with bust of Augustus, ca. 25 BCE, Louvre-Lens, Lens


After the Battle of Actium, the Mediterranean became known as Mare Nostrum (Our Sea), while the legions were demobilized or transferred to the outer frontiers. It was the beginning of two hundred years of peace and prosperity, known also as Pax Romana. Marcus Agrippa played a crucial role in establishing and shaping those crucial first years of the Roman Empire.  


In 28 BCE, Agrippa served as consul with Octavian. A second consulship was unusual, and that Octavian wanted to share the supreme office with Agrippa was a testament to the strong bond between the two. The same year both men took the roles of censors, gaining absolute power. No one could oppose a censor’s decision, and only a censor’s successor could cancel it. As censors, Octavian and Agrippa held control over state finances, oversaw public works, and took a census of Roman citizens and their property (the first since 71 BCE). 


Next year, Agrippa held his third consulship with Octavian. The same year, in 27 BCE, the Senate bestowed upon Octavian the imperial title of Augustus. As a consul, Agrippa persuaded the Senate to give Augustus control over frontier provinces and, more importantly, the armies’ command in the area. Initially, the arrangement was valid for ten years, but eventually, Augustus would assume the monopoly over the imperial military. 


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Coin of Augustus with Augustus and Agrippa seated together on the reverse, 13 BCE, The British Museum, London


In 23 BCE, Augustus fell ill, and it was believed that he was going to die. Recognizing that the only other person who could keep his empire together was Agrippa, Augustus gave him his signet ring, symbolically thereby recognizing Agrippa as his heir. The special bond between the two men aroused the envy of Augustus’ nephew, Marcus Claudius Marcellus. Agrippa, who did not get along with him, left Rome and went to the East. 


Formally, he was appointed the governor of Syria, but he sent a legate to govern the province instead, and for the next two years he remained on Lesbos and governed by proxy. It seems that there could be more to this story. During this time Agrippa was able to return the legionary standards lost to the Parthians when they defeated Crassus at Carrhae years ago. The return of the eagles was a great achievement, and it is very probable that Augustus appointed his most trusted man for such a task.


During his stay in the East, Marcellus died, and upon his return to Rome in 21 BCE, Agrippa was given the hand of Augustus’ daughter, Julia. Agrippa was already married to Augustus’ niece Marcella, but now he was officially a part of the imperial family. Julia was Augustus’s only child, and Agrippa’s children would be imperial heirs. Julia would give Agrippa three sons, as well as a daughter named Agrippina. It would be through Agrippina that Agrippa’s descendants would ultimately rise to the throne: his grandson Caligula followed by his great-grandson Nero.


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Audience with Agrippa, Sir Lawrence Alma-Tadema, 1876, The Dick Institute, Kilmarnock


Agrippa did not stay in Rome for long. In 20 BCE he was again in Gaul, where he quelled yet another riot, regulated the taxation system, and undertook a major road construction. A year later he was sent to Spain, where the Roman army suffered huge losses in guerilla warfare. It was not an easy campaign, but Agrippa emerged victorious. After two centuries of unrest, the Iberian Peninsula was pacified for good. The Roman Senate, at the behest of Augustus, voted to award Agrippa a triumph. Again, he declined the honor. In 17 BCE, Agrippa was sent to govern the eastern provinces for a second time. It was during that period that he met king Herod, and two men became close friends. Agrippa’s just and prudent administration won him the respect and good-will of the provincials, especially that of the Jewish population, which was a feat that even the so-called “good emperors” were not able to achieve. Agrippa restored the effective Roman control over the Crimean Peninsula during that period as well.


The Architect And Scholar

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Marcus Agrippa planning the construction of the acqua Virgo, Giovanni Battista Grossi and Andrea Bergondi, 1730s, Trevi Fountain, Rome, via Daily Art Magazine


On his deathbed, Augustus famously quipped that he “found Rome as a city of brick and left it a city of marble.” It was Agrippa who supplied that marble, often on his own initiative. When not engaged on the battlefield, Agrippa was involved with Rome’s urban development and the provinces. During the Triumvirate, Agrippa assumed the office of aedile, a magistrate who oversaw Roman public buildings and festivals. This was an unusual choice, especially for a former consul and a victor over Sextus Pompey’s fleet. Nevertheless, Agrippa carried this civic duty with the same competence that he demonstrated on the battlefield. 


The beginnings of Agrippa’s passion for building projects can be traced to his work on Portus Julius, which would gradually develop into a major naval base. In Rome, Agrippa enlarged and repaired the decaying sewage system, known as Cloaca Maxima. Then he embarked on an ambitious project of restoring Rome’s grand aqueducts. He repaired the Marcian aqueduct (aqua Marcia), Rome’s longest aqueduct, and built a new aqua Julia. Later, during the Empire, Agrippa built aqua Virgo, the aqueduct that is still in operation today, supplying many of Rome’s fountains, including the Trevi. To secure easy access to potable fresh water for all the capital’s inhabitants, Agrippa organized a network of hundreds of fountains. He is also responsible for the creation of Rome’s first public baths – Thermae Agrippae – unrivaled in size and engineering before Trajan’s baths.


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The Pantheon in Rome, built under Agrippa, rebuilt in 113-125 CE, via Nat Geo


Agrippa is best known for building the Pantheon, probably the best-preserved Roman building in the world. The original structure would later burn down and was rebuilt by emperor Hadrian, who kept Agrippa’s original inscription on the building’s façade. Agrippa was busy in the provinces too. Caesar conquered Gaul for Rome, but Agrippa was the one who urbanized the region. On the bank of the Rhine, he established a town that would become known as Colonia Agrippinensis (present day-Cologne). He also improved existing provincial towns, building theatres and temples, like the one in Nimes. Always a workaholic, Agrippa built a road-network in Gaul, known as via Agrippa, 21 000 km in length. This, improved communication lines and access across the territory. 


One of the most traveled men of his time, Agrippa mapped Augustus’ “imperium sine fine” (the empire without an end). The surveys, known as Dimensuratio provinciarum, and Orbis terrarum, were completed by Agrippa’s sister after his death and engraved by Augustus on the floor of Porticus Vipsania. It remained the reference map of the world throughout Roman and medieval times. 


Lastly, the measurement for a Roman foot was standardized around this time. The standard was nothing less than Agrippa’s own foot. An imperial Roman mile, still in use in some parts of the world denotes 5,000 Agrippan feet. A man of many talents, he was also a writer. However, his biography and his treatise on Geography, are sadly lost.


An Unexpected End

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Dupondius showing Augustus and his friend Agrippa on the obverse, with crocodile tied to a palm branch on reverse, 9-3 BCE, The British Museum, London


By 18 BCE, Agrippa was the emperor in all but in name. Augustus arranged for the Senate to grant his friend proconsular powers (maius imperium proconsulare), which gave him military precedence over all other army commanders, excluding the emperor. He was also given tribunal powers (tribunicia potestas), allowing him to summon the Senate and People’s Assembly and introduce legislation as he saw fit. Like the emperor, his person too was sacrosanct and immune from prosecution. The two close friends’ joint rule was commemorated by coinage representing Augustus and Agrippa together, like the famous Dupondius of Nemausus (above image).


In the fifth decade of his life, Marcus Agrippa was still not prepared to retire. When Illyrian tribes revolted in 13 BCE, he personally took command of the troops and achieved another victory. It was to be his last. Upon the return to Italy in 12 BCE, Agrippa fell ill. Hearing the news of his friend’s predicament, Augustus rushed to join him. But he was too late. Marcus Agrippa died in his villa. He was just 51. Augustus gave the eulogy at his friend’s funeral and spent a month in mourning. As the last honor to his closest friend and companion, Augustus buried Agrippa in his own mausoleum


Agrippa: A Lasting Legacy

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Relief from Ara Pacis, showing the imperial family, Augustus is at the far left and Agrippa hooded on the right, 9 BCE, Museo Dell’ Ara Pacis, Rome


If Augustus is considered the greatest of the Roman emperors, then Marcus Agrippa should be one of the greatest Romans. 


A man of many talents, Agrippa played an instrumental role in building the Roman Empire and ensuring its lasting success. As a general and admiral, he secured the throne for Augustus. As a statesman and diplomat, he strengthened the empire’s foundation. As an architect and engineer, he improved the lives of the empire’s citizens. While as a scholar, Agrippa showcased imperial achievements for all to see. Above all that, he remained a close and faithful friend and companion to Rome’s first emperor. Rejecting triumph after triumph, Marcus Agrippa remained a humble man, unwilling to upstage Augustus. And the first Roman emperor rewarded this loyalty. Agrippa was granted status and powers second only to the emperor, and ruled jointly with his friend, August, for a time. Finally, he became a member of the imperial family. 


Even after his early death, Agrippa’s contribution continued. His sons, Gaius and Lucius, would both suffer untimely and premature deaths, but his daughter Agrippina would marry Germanicus, and ensure the survival of the Julio-Claudian dynasty, through Agrippa’s grandson Caligula, and great-grandson Nero. Despite all his achievements, ancient historians largely ignored Marcus Agrippa. But history can be a curious thing.


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The Pantheon in Rome, with the inscription commemorating Marcus Agrippa, via Civitatis Rome


If you find yourself in Rome, take a stroll to the Pantheon and look at the large letters on its façade: M·AGRIPPA·L·F·COS·TERTIVM·FECIT. Once you translate the Latin and the abbreviations, you will get: “Marcus Agrippa, son of Lucius, built this when he was consul for the third time.” Even though rebuilt and renovated by subsequent emperors, and then converted into a church, the name of Agrippa remained the most prominent one on the building. For a man who was the main pillar of the Roman Empire, there is not better testament than this monumental building in the heart of Rome that more than two thousand years later, still stands the test of time.

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By Vedran BiletaMA in Late Antique, Byzantine, and Early Modern History, BA in HistoryVedran is a doctoral researcher, based in Budapest. His main interest is Ancient History, in particular the Late Roman period. When not spending time with the military elites of the Late Roman West, he is sharing his passion for history with those willing to listen. In his free time, Vedran is wargaming and discussing Star Trek.