Lepidus was a among Julius Caesar's greatest supporters. He started his cursus honorum as a praetor in 49 BC, and was rewarded with the consulship in 46 BC, after the defeat of the Pompeians in the East. Following Caesar's assassination in March 15 44 BC (the calends of March, Lepidus allied himself with Marcus Antonius in a joint bid for power. But Caesar had left an heir: Octavianus, his great-nephew and adopted son, had a matching ambition and the popularity with the to climb the hierarchy. Together they formed the second triumvirate, legalized with the name of Triumvirs for the Organization of the People by the Lex Titia of 43 BC. The triumvirate had a legal life span of five years and was renewed in 38 BC for an equal period of time.
After the pacification of the East and the defeat of the assassins faction, during which Lepidus remained in Rome, he went to rule the western provinces of Hispania and Africa. Somehow Lepidus managed to remain aside the frequent quarrels between his colleagues Antonius and Octavianus. However, in 36 BC, an ill-judged political move, was the excuse that Octavianus needed. Lepidus was accused of usurping power in Sicily and attempt of rebellion and was forced to exile. All of his offices were taken away, except the one of pontifex maximus.
Lepidus died peacefully in 13 BC.