The Roman Assassins, known at the time as the Liberalis Circulum (English: Circle of freedom), were the Brotherhood of Assassins who operated on the territory controled by the Ancient Rome during the times of the Roman Republic and the Roman Empire.
One of the most early known iteration of the Assassin Order, the Liberalis Circulum was founded during the early Roman times. One of its founder, Lugos, traveled to Egypt to recover two Pieces of Eden founded in a pyramid by Roman plunderers , the Ankh and the Scepter of Aset. Coming back to Rome by sailing across the Mediterranean Sea, Lugos died when a waterway accidentally opened, causing the ship and its cargo to sink. 
In 44 BCE, forty Senators, secretly Assassins, conspired against the Roman general and dictator Gaius Julius Caesar. They met in a secret cave underneath where the Santa Maria in Aracoeli would later stand and designed plans for the assassination, led by Marcus Junius Brutus and Gaius Cassius Longinus.
Deeper inside the cave, Brutus discovered an ancient vault, where he received visions of Caesar's future assassination. This motivated Brutus more, and on 15 March 44 BCE, the Assassins stabbed Caesar to death.
Later, Brutus was eventually defeated in battle at Philippi by Marcus Antonius, and committed suicide shortly thereafter. When the Roman Assassins found his body, they tried to revive him using the Shroud of Eden, however, he was only revived for a brief moment, before ultimately dying once more.
In 259, Aquilus, an Assassin located in Lugdunum, was tasked to eliminate two Generals and a Senator and then retrieve an artifact in possession of his cousin Accipiter, an Assassin and a General of the Alemanni tribes. As Aquilus reached his third target, the General Gracchus, his intent was discovered and he was stabbed by his own target. Luckily, Aquilus was saved by his cousin who gave him the Ankh, which had been finally recovered, centuries after Lugos' death. The Gaul took back the artifact to Lugdunum, but it was then stolen by the Assassins's ancestral ennemies, with Caïus Fulvus Vultur killing Aquilus' father, Lucius. 
The vengeful son then tracked down the conspirators up to Rome, where he eliminated them and retrieved the artifact before returning home. Later, the arrestation and the execution of Aquilus were ordered by the prefect of his home city, but even if Aquilus was killed, the artifact was succesfuly hidden. The same prefect with which Cuervo, an Iberian Assassin sent to preserve the Circle's interests in Lugdunum from the Germanic armies raiding the Empire, and Accipiter were negociating the spare of the Roman city in exchange for a significant tribute to the Alemanni.
- Gaius Cassius Longinus
- Marcus Junius Brutus
- 38 other senators involved in Caesar's assassination
- Lucius (Gaul)
- Aquilus (Gaul)
- Accipiter (German)
- Cuervo (Iberian)