He was present in the senate-chamber on the day of the assassination.

He stole secretly away when he saw that the deed was done, and repaired to the camp of the army without the city and immediately assumed the command of the forces.
This gave him great power, and in the course of the contests which subsequently ensued between Antony and Octavius, he took an active part, and held in some measure the balance between them.

At length the contest was finally closed by a coalition of the three rivals.

Finding that they could not either of them gain a decided victory over the others, they combined together, and formed the celebrated _triumvirate_, which continued afterward for some time to wield the supreme command in the Roman world.

In forming this league of reconciliation, the three rivals held their conference on an island situated in one of the branches of the Po, in the north of Italy.