Explanation: Agrippa was the right-hand man and foremost commander of Augustus. The thing is, while Augustus was an incredible politician, his own military record was middling - not great, not terrible. Agrippa, on the other hand, rose from plebeian origins to an incredibly talented and renowned commander - something quite important considering he rose to prominence in the middle of a civil war! Agrippa served Augustus faithfully throughout the civil war and into Augustus's ascension to the (uncodified) position of Emperor.
He and Augustus were reportedly quite close friends, not just allies, and upon Agrippa's death at the relatively young age of 50, Augustus spent a month in mourning and saw that Agrippa's remains were interred in Augustus's own (quite magnificent) familial mausoleum.