Role of the Guard in Power Struggles

1st c. CE

The exclusive privileges and power of the Prefecture practically ensured that Prefects would involve themselves in dynastic intrigue, the problems of succession that plagued the imperial office from the death of the first Emperor to the very last.  The sons of Tiberius died before him, as did his former favorite Sejanus.  Tiberius spent the waning months of his life without a clear choice of heir.  Upon Tiberius' death in 37 CE, Quintus Sutorius Macro, the Praetorian Prefect who replaced Sejanus, helped bring Gaius Caligula, Tiberius' immortally-infamous grandson,  to the throne.  Caligula ruled only four years, since his mad cruelty engendered such resentment among the Guard officers responsible for his safety that in 41 CE, they murdered him.

In the chaotic days that followed, the Republic came close to being restored.  But before the Senate could act, the Praetorians thrust an unexpected successor forward -- Claudius, Caligula's handsome but laughably clumsy uncle, whom the guilty Guardsmen had found cowering behind a curtain as they looted the imperial palace.  The Praetorians carried Claudius to their headquarters and proclaimed him Emperor, heedless of the will of the Senate.  In spite of the illegitimate elevation, the Senate could do nothing but ratify the Praetorians' choice, or risk further bloodshed.  The Senate acquiesced, their chance to rescue the Republic slipping away for good.

Claudius knew that he owed the Praetorians everything, and had seen first-hand how they could take it all away, without consequence.  To garner their goodwill, he ordered a payment of five years' salary to each Guardsman, calling the spectacular donative a "gift" to celebrate his accession to the throne.  While the gesture might have bought his safety from the Guard, no amount of money could protect Claudius from his own family.  He was poisoned by his wife Agrippina and stepson Nero, whom the Praetorians embraced willingly as Emperor, ignoring the taint of his guilt in the murder of Claudius their benefactor.

Nero was as unbalanced as Caligula, although his extreme tendencies were moderated in part by Nero's advisers, notably the Praetorian Prefect, Sextus Afranius Burrus.  After Burrus died, Nero spun completely out of control and managed to alienate nearly everyone around him, even his mother Agrippina who had murdered her husband Claudius to place her son on the throne.  In 65 CE, Nero narrowly avoided the threat of conspiracy, thanks to the Prefect Tigellinus, who hunted down the plotters mercilessly.  The list of conspirators even included Tigellinus' fellow Prefect, as well as a number of other officers of the Praetorian Guard.  All were condemned and the Guard received a bounty of 500 denarii for their loyalty -- more accurately, lack of participation -- in the conspiracy of Piso.

Three years later, after further outrageous behavior, Nero faced a worse threat: a serious rival for his throne, supported by the Guard who abandoned Nero at the behest of their new Prefect, Nymphidius Sabinus.  Not even Tigellinus could save Nero, who in his isolated desperation committed suicide.  The pretender, Galba, had made a promise to the Guard of 30,000 sesterces for each man, but he alienated many Praetorians when he unwisely reneged on his word.  Otho, another emerging claimant, exploited the opportunity by bribing 23 Guard cavalrymen (speculatores) to announce him as the new Emperor.  Although the Praetorian cohors on duty at the time opposed the coup, the confusion gave Otho the time he needed to sway the rest of the Guard to his side.  Galba paid with his life for the promise he could not keep to his Guardsmen.
 
69 CE came to be called the "Year of the Four Emperors."  Galba had been slain by the Praetorian sponsors of Otho, who himself was defeated by a third candidate, Aulus Vitellius, governor of Germania Inferior.  Although he had the formidable support of the Danubian legions, Otho lost on the field of Bedriacum in part due to the poor performance of the Praetorian Guard, whose soldiers had seen no field experience for almost 100 years.

Vitellius wasted no time pulling the fangs of the Guard who had opposed him.  Suetonius says he ordered 120 Praetorians implicated in Galba's murder to be summarily executed and discharged the remaining Guard soldiers without severance.  Vitellius then rebuilt the Guard out of the cadre of his own loyal German legionaries, while the former Guard members, actively seeking vengeance, fled Italy to join the camp of yet a fourth would-be Emperor, Titus Flavius Vespasianus, governor of Syria.  Vespasian swiftly marched west and crushed Vitellius at Bedriacum, the same bloody plain where Vitellius had defeated Otho.

After his ultimate victory, one of Vespasian's first acts was to return his loyal ex-Praetorians to the ranks of the Guard.  In an abrupt reversal of fortune, heads rolled as the old Guard replaced the new.  Vespasian solidified his hold on the loyalty of the Praetorians by appointing his elder son, Titus, as Praetorian Prefect.  From this time forward, the command of the Guard would be the highest post an equestrian noble could obtain.

Vespasian and his sons who ruled after him, Titus (79-81 CE) and Domitian (81-96 CE), commanded the loyalty of the Praetorian Guard as securely as any Emperor had since Augustus.  Domitian made heavy use of the Praetorians in his campaigns against the Germans as well as in Dacia.  The Praetorians were heavily engaged in combat, so much so that in 87 CE, one of their Prefects, Cornelius Fuscus, was slain in battle.

Domitian, though capable, proved susceptible to the intrigues of the Senate.  Unwilling to flatter them and possessed of a suspicious nature bordering on the paranoid, Domitian made enough enemies that in 96 CE he was assassinated by a group of them, including the Prefect Petronius Secundus.  The Senate nominated Marcus Cocceius Nerva, an aging senator whom the brooding Praetorians felt responsible for their beloved Domitian's death.  They demanded that the new Emperor order the execution of Petronius Secundus for his part in the murder.  Fearing for his own life, Nerva gave the order.

Faced with the growing resentment of the Guard, Nerva sought a powerful ally to counterbalance the Praetorian animus.  He found his ally in Marcus Ulpius Traianus, governor of Germania Superior.  Trajan commanded the German legions and as heir, could be confidently expected to avenge Nerva should the Praetorians harm him.