The presence of a fastigium – a Latin word meaning ‘slope’ or ‘summit’ but which refers to the triangular structure above the pronaos – suggests it was similar in appearance to the pediment of Hadrian’s Pantheon, and thus its front elevation was traditional and Greek in style.¹⁵⁰ The enclosed space in a pediment was often filled with statues depicting mythological stories of gods or heroes. The design scheme created by Diogenes of Athens for the decorations is entirely lost. However, the statues Pliny refers to may have been placed not in, but on top of the fastigium, located on platforms at each end and on the apex, which were common features of Roman public buildings and are often depicted in images of temples shown on coins.

The reason for Diogenes’ choice of caryatids as columns is not clear. The Roman architect Vitruvius writes,

Unless acquainted with history, he will be unable to account for the use of many ornaments which he may have occasion to introduce. For instance; should any one wish for information on the origin of those draped matronal figures crowned with a mutulus and cornice, called Caryatides, he will explain it by the following history. Carya, a city of Peloponnesus, joined the Persians in their war against the Greeks. These in return for the treachery, after having freed themselves by a most glorious victory from the intended Persian yoke, unanimously resolved to levy war against the Caryans. Carya was, in consequence, taken and destroyed, its male population extinguished, and its matrons carried into slavery. That these circumstances might be better remembered, and the nature of the triumph perpetuated, the victors represented them draped, and apparently suffering under the burthen with which they were loaded, to expiate the crime of their native city. Thus, in their edifices, did the ancient architects, by the use of these statues, hand down to posterity a memorial of the crime of the Caryans.¹⁵¹

As Pliny describes them, the caryatid-shaped columns would likely have appeared as they do in the ‘Kore Porch’ (Porch of the Maidens) of the Erechtheion on the Acropolis of Athens. The Erechtheion offers an interesting analogue for the Pantheon. The main building was sacred to Athena Polias and Poseidon Erechtheos with adjoining sacred precincts for holy relics, which included the score marks left by Poseidon’s trident as it struck the acropolis, an olive tree, and various altars to Hephaistos and an Athenian hero named Boutos.¹⁵² In the Erechtheion the draped caryatid figures form the shafts of six columns with Ionic capitals above their heads. In Agrippa’s building these shapely columns may have supported the roof of the pronaos or surrounded the main wall of the rotunda as the regular fluted columns do in the round, roofed Temple of Hercules Victor in the Forum Boarium or the tholos-style ‘Temple B’ in the Largo Argentina in Rome.¹⁵³ From the outside Agrippa’s Pantheon may have looked like the Thomas Jefferson Memorial in Washinghton, D.C., designed by the architect John Russell Pope and completed in 1943, though its rotunda is surrounded by Ionic columns, not caryatids.¹⁵⁴ That building is open on all sides to let in light and air. The caryatids of Agrippa’s building may have stood on a low wall – like the Erechtheion – forming the rotunda which supported a tiled roof, unless the space was left open to the sky.

The entrance to the original structure may once have borne the now famous inscription:

M· AGRIPPA ·L · F ·COS· TERTIVM· FECIT¹⁵⁴

M. Agrippa, son of Lucius, Consul three times, made [this].

However, the bronze letters on the present building (plate 17) are faithful modern copies – even the iconic pediment with its entablature, which today bears them, probably does not date from Agrippa’s time.¹⁵⁵ The inscription may have been designed specifically for the Hadrianic edifice as a homage to its original builder, since he is known to have scrupulously retained original dedications after he restored buildings.¹⁵⁶ The formula of the inscription is problematic for a temple. One scholar has pointed out that it does not specify a god, as would be expected of a temple, that it is not a votive dedication, nor actually a dedication at all.¹⁵⁷ One compelling theory identifies the Pantheon as a monument commemorating Agrippa’s victorious land battles, dedicated to Mars, complementing as it does the neighbouring Basilica Neputini, dedicated to Neptunus, which celebrated his successes at sea.¹⁵⁸ Placing the statues of Agrippa and Augustus outside, as the joint victors, makes sense in this context. The figure of Iulius Caesar, located close by the entrance, would have represented a divine link between the mortal men outside and the Olympian gods Mars and Venus inside.¹⁵⁹ Further it is possible the statue of Iulius Caesar gazed out across the Campus to the final resting place of the man who inherited his name. The Fasti Frati Arvalum, a list of public holy days, maintained by the Arval Brothers – the aristocratic organization which came to be responsible for sacrifices on behalf of the imperial family and of which Agrippa was a member – shows an entry made some time after 12 BCE in the addendum for 23 September for gods in the Campus Martius:

HOLY DAYS BY DECREE OF THE SENATE ON THE BIRTHDAY OF IMPERATOR CAESAR AUGUSTUS, PONTIFEX MAXIMUMS: MARS, NEPTUNUS IN THE CAMPUS; APOLLO AT THE THEATRE OF MARCELLUS.¹⁶⁰

Significantly all three gods listed – divine patrons of Augustus and Agrippa – are the di Actii associated with victory in the Actian War.¹⁶¹ As the Pantheon was paid for by Agrippa, he may have always intended it to be a private shrine (sacrum privatum) and not a public temple (aedes publica), since he did not arrange for it to be consecrated according to religious law; but he did make it – like the Basilica of Neptunus – accessible by the public.¹⁶² Augustus’ Temple to Apollo Actius located beside his own house on the Palatinus was also such a private shrine. As Roman public opinion did not approve of victory celebrations over fellow Romans – Sex. Pompeius and M. Antonius in Agrippa’s case – erecting the Basilica and Pantheon was a politically acceptable way for him to mark his military successes and to express his gratitude to the appropriate gods.¹⁶³ Yet it is also possible that the iconic inscription, which has come to symbolize the building, may not have been what Agrippa originally wrote on it at all.¹⁶⁴ The original appearance and meaning of Agrippa’s Pantheon remain frustratingly enigmatic.

The design of the interior space of Agrippa’s Pantheon is also a mystery. The present rotunda has a diameter of 43.3m – 2.3 times that of Temple B in the Largo Argentina. Curious is that Pliny’s description of the original building focuses on the art decorating the front, yet he says nothing of the main structure, whereas Dio specifically mentions the vaulted roof of the later structure which he says ‘resembles the heavens’.¹⁶⁵ Pliny was writing about the building dating from Agrippa’s time and his silence about the interior of the rotunda, in comparison to Dio who was describing the Hadrianic rebuild, perhaps hints at a restrained style of decoration – one suited to the rustic sensibility of its client – that did not merit particular comment. Unless new sources dating to antiquity are found, it is unlikely we will ever know what a visitor to the original Pantheon saw shortly after its opening when he went inside.

It may have been during this period that the foundations were laid for Agrippa’s own final resting place. Called the Sepulchrum or Aedes Agrippae (fig. 12) its exact location is not known with certainty, though if the remaining letters on fragments of the so-called ‘Marble Map of Rome’ dating to the later Severan period are of this monument, it may have stood between the villa Publica and the Baths of Agrippa in the modern Via del Gesù.¹⁶⁶ It may have been built using marble shipped in from Agrippa’s own quarries located in Phrygia.¹⁶⁷

The question inevitably arises about how much Agrippa was personally involved in these civil engineering projects? As he was paying for the works out of his own pocket he must have taken a very active interest, at least selecting the architects and agreeing the designs, contributing ideas about the features or critiquing the final appearance of the buildings. Based on his earlier enthusiasm as aedile for hydraulic engineering projects, in which he is known to have inspected Rome’s main sewer or the Portus Iulius in person, he was probably a regular visitor to the construction sites, checking on the quality of building materials and encouraging the civil engineers, craftsmen and labourers on-site to work harder and faster. This would have been particularly true of the Pantheon where the building may have had his own name on it. Agrippa would likely have consulted Augustus before he departed about his intentions for the development of the Campus: seemingly everything he did was done with his friend’s best interests in mind, and carried out with his approval.

Loyalties and Rivalries

What motivated Agrippa to spend his own money on these lavish edifices in the Campus and to dedicate them to memorializing the cause of Augustus? Dio suggests that he did it ‘not out of any rivalry or ambition on Agrippa’s part to make himself equal to Augustus, but from his hearty loyalty to him and his constant zeal for the public good’; Augustus’ response to his friend’s fidelitas and humanitas ‘so far from censuring him for it, honoured them the more’.¹⁶⁸ Augustus knew only too well how fortunate he was to have such a friend in whom he had absolute trust.

It must have been clear to all that of his closest friends and advisers Agrippa was now Augustus’ right-hand man. He had proved more loyal than Salvidienus, and he had exceeded Messala and Taurus in carrying out his missions. Yet Augustus also favoured the friendship of Maecenas. Historian Velleius Paterculus describes Maecenas as a man:

of equestrian rank, but none the less of illustrious lineage, a man who was literally sleepless when occasion demanded, and quick to foresee what was to be done and skilful in doing it, but when any relaxation was allowed him from business cares would almost outdo a woman in giving himself up to indolence and soft luxury. He was not less loved by Caesar than Agrippa, though he had fewer honours heaped upon him, since he lived thoroughly content with the narrow stripe of the equestrian order.¹⁶⁹

Where Agrippa had doggedly fought to ensure Augustus was the victor of the civil wars, Maecenas had been the reliable representative back in Rome, tirelessly standing up to his pro-Antonian foes. While Agrippa had built harbours for a navy and fortifications for an army, Maecenas built a network of financiers and politicians; but he also assembled a team comprised of the best talent in Latin creative writing.¹⁷⁰ Words and music would be their weapons in the war of ideas. Sometime before 37 BCE he had met Vergilius Maro and was deeply impressed by his work. Vergil showed his gratitude by dedicating the Georgics to him, which he finished in 29 BCE. Vergil, in turn, introduced him to another up and coming poet, Horatius Flaccus (Horace). Also benefiting from Maecenas’ patronage were Propertius, and the lesser poets Domitius Marsus, Varius Rufus, Valgius Rufus and Plotius Tucca. Soon Maecenas became known as a patron for the greatest poets of the new age of Augustus.

What, then, was the manner of Agrippa’s relationship with Maecenas? It was probably not an easy one. There is an implication in one surviving account that Agrippa was no great lover of florid writing with obscure words. Suetonius mentions a M. Vipsanius who could be our M. Agrippa. He is reported to have:

called Vergil a superstitious child of Maecenas, that inventor of a new kind of affected language, neither bombastic nor of studied simplicity, but in ordinary words and hence less obvious.¹⁷¹

That somewhat contemptuous view of artifice in language would, however, be consistent with Agrippa’s known preference for rustic simplicity in architecture, painting and sculpture.¹⁷² In many ways, the two men were diametric opposites: Agrippa, the man from an undistinguished family from outside Rome, compares with Maecenas, the descendant of Etruscan aristocracy and a respectable bloodline; Agrippa, a man willing to put himself in harm’s way on land and sea in pursuit of victory for his friend, in contrast to Maecenas, who stayed in Italy, using personal connections and persuasion to build a consensus favourable to the cause he supported; Agrippa, the master builder and commissioner of works shaping great structures in wood, brick, stone and marble which brought water and visual beauty to the city, as opposed to Maecenas, a curator of poets, a lover of self-indulgent pleasures and the easy life. Their only common ground was their friendship with Augustus. It did not mean they had to like each other. While there is no direct evidence of conflict between the two men, it is easy to imagine Agrippa at times feeling frustration with, or even contempt for, Maecenas for being a dandy and a rake, and Maecenas for perceiving Agrippa as a man lacking in sophistication and an appreciation for the finer things in life, as someone who did not know how to have fun.

There was little to enjoy where Augustus was residing. He was personally directing military operations in northern Spain, which he had initiated in the spring of 25 BCE from his base in Segisama (Sasamón). He hoped this would be the final phase in the conquest, completing a haphazard process which had begun in 218 BCE.¹⁷³ Successive campaigns had been undertaken by eager generals, but the gains had been won at high cost and the spoils to pay for them proved disappointing. Ambitious Roman consuls preferred to seek glory in the East, where rich rewards awaited and a commander could rather more expeditiously gather political and financial capital to build up his personal prestige among his peers and provide for a comfortable life in retirement in a villa on the Campanian coast. The last corner of Hispania libera was inhabited by two proudly independent nations, the Astures and the Cantabri. Augustus believed that a concentrated military campaign would finally break the resistance of these people. So confident of victory was he that he took with him 18-year-old Ti. Claudius Nero, son of his wife Livia, to begin his military career as a tribunus militum.¹⁷⁴ Assisting him were his legati C. Antistius Vetus and P. Carisius, but the same source also mentions Agrippa was involved, which is problematic since he was in Rome at this time.¹⁷⁵ The Iberian nations proved quite able to stand up to the Romans. The legions’ progress was impeded as heavily armed soldiers trained to fight in set piece battles on open plains were forced to fight a guerrilla-style war in the hills and valleys.¹⁷⁶ Then, as he so often did during wartime, Augustus fell ill. Dio suggests overexertion and anxiety, though typhoid is suspected.¹⁷⁷ He was swiftly transferred to Tarraco on the Mediterranean coast, where he remained in the care of Livia and his personal physician.¹⁷⁸

Meanwhile, in Rome, Augustus’ 14-year-old daughter Iulia the Elder was due to marry his 17-year-old nephew, M. Claudius Marcellus (plate 27).¹⁷⁹ He had hoped to preside in person at the wedding, but his poor health prevented him from travelling on the long journey back to the city. To stand in his place and give away his daughter’s hand to her new husband – a singular honour given Iulia was his only child – Augustus appointed Agrippa.¹⁸⁰ Augustus gradually recovered and, left the prosecution of the Bellum Cantabricum et Astruricum in the hands of his deputy Antistius, and the governance of the Roman province to L. Aemilius.¹⁸¹ It must have occurred to him that this was a job ideally suited for Agrippa, but for the time being he had other plans for his friend. The deflated commander-in-chief returned to Rome in 24 BCE. As he approached the city he sent ahead of him a letter promising 400 sestertii to each citizen but insisted it be approved by the Senate first before being made public.¹⁸² When he reached Rome new honours were given to him for his safe return by a grateful city.

It would have been a great relief for Agrippa to be able to greet his friend again. In another mark of Augustus’ gratitude and friendship, when the house on the Palatinus, which had belonged to Antony but had later been given jointly to Agrippa and Messalla, burned down, Augustus gave money to Messalla, but insisted that Agrippa move into his own house.¹⁸³ Dio writes ‘Agrippa not unnaturally took great pride in these honours’.¹⁸⁴

The scare caused by Augustus’ debilitating sickness raised the uncomfortable issue of what would happen when he died. Speculation turned to Marcellus, who was seen by many as the rising star in the imperial family. On Augustus’ return to Rome Marcellus was granted several privileges and promotions aimed at accelerating his political career, perhaps even with him as successor in mind.¹⁸⁵ Young and inexperienced, he was also given the right to become a senator among the expraetors and to stand for the consulship ten years earlier than was customary.¹⁸⁶ These concessions were also extended to Livia’s sons Tiberius and Nero Claudius Drusus – who Augustus had not adopted as his own – who were permitted to stand for each magisterial office on the career ladder five years before the regular age; Tiberius was at once elected quaestor, while Marcellus was appointed aedile.¹⁸⁷ Agrippa was 30-years-old when he first became aedile, so it was quite an extraordinary concession to the ‘mere strippling’, as Tacitus calls the young man.¹⁸⁸ Augustus’ seeming favouritism for his nephew over his best friend caused some to speculate on trouble later:

People thought that, if anything should happen to Caesar, Marcellus would be his successor in power, at the same time believing, however, that this would not fall to his lot without opposition from M. Agrippa.¹⁸⁹

Other than Paterculus, no other Roman historian makes this assertion, but writing around a half century after the events, he may have had access to contemporary records later historians did not which mentioned the rumours. What people thought, of course, may not have been what Agrippa himself thought. If, in fact, Agrippa did harbour resentments towards the young man, scrupulous to a fault, he kept them private. Augustus, for his part, was smart enough to realize that his nephew had much to learn and that he was very far from ready to take on the mantle of supreme power.¹⁹⁰ Yet he was also keen to promote the notion of a Res Publica where men enjoyed freedom, and to avoid creating the impression that he was founding a monarchical dynasty – regardless of whether his eventual successor was Marcellus or Agrippa. As Dio articulates the conundrum,

he either wished the People to regain their liberty or for Agrippa to receive the leadership from them. For he well understood that Agrippa was exceedingly beloved by them and he preferred not to seem to be committing the supreme power to him on his own responsibility.¹⁹¹

If Agrippa’s ignoble origins were despised by the patricians, they played well with the plebs.