According to the Roman historian Tacitus, the barracks were built in 23 AD by Lucius Aelius Sejanus, the praetorian prefect serving under the emperor Tiberius, in an effort to consolidate the several divisions of the guards.

On March 28 193 AD Titus Flavius Claudius Sulpicianus was within the barracks trying to calm the troops when he began to offer a donative if they would support his candidacy for the throne.

Meanwhile, Didius Julianus also arrived at the camp, and since his entrance was barred, shouted out offers to the guard.

The guards closed with the offer of Julianus, threw open the gates of the camp, and proclaimed him emperor.

[3] Their last stand was at the Battle of the Milvian Bridge in 312 AD, and after Constantine's victory he officially disbanded the Praetorian Guard, sending them out to different corners of the empire.