The organization newly founded in Egypt was dedicated to fighting against the Order of the Ancients, of whom the Roman dictator Gaius Julius Caesar was a leading member. Many Roman senators were united in their hatred of Caesar when they joined the Hidden Ones. On 15 March 44 BCE, they called a Senate meeting at the Theatre of Pompey to lure Caesar into a trap and assassinate him. Caesar, without an ally in sight, fell right into their grasp as the crowd of senators surrounded him, blades drawn. Greco-Egyptian co-founder Amunet struck the first blow, whereupon Decimus and the other Hidden Ones frenziedly stabbed him to death.
Behind the scenes
Historically, Decimus Junius Brutus Albinus was one of the chief organizers of Julius Caesar's assassination, an event depicted in the memory "Fall of an Empire, Rise of Another" of Assassin's Creed: Origins. None of the senators present at the assassination is identified as him in the game, but his presence there is confirmed in the official game guide.