Marcus Vipsanius Agrippa was an early supporter of Augustus (then "Octavius") during the Final War of the Roman Republic that ensued as a result of the assassination of Julius Caesar in 44 BC. He was a key general in Augustus' armies, commanding troops in pivotal battles against Mark Antony and Sextus Pompeius. From early in the emperor's reign, Agrippa was trusted to handle affairs in the eastern provinces and was even given the signet ring of Augustus, who appeared to be on his deathbed in 23BC, a sign that he would become "princeps" were Augustus to die. It is probable that he was to rule until the emperor's nephew, Marcus Claudius Marcellus, came of age. However, Marcellus died that year of an illness that became an epidemic in Rome.