 Complete the following phrase:  Augustus did the unspeakable in 28 BC and erected a mausoleum on the Campus Martius, a previously public land upon which infrastructure was normally illegal. This challenged his claim to be Princeps, as his enemies found such an action to be too ambitious for a regular citizen and thus above the law. Notable features of the mausoleum included a bronze statue of Augustus, pyres, and Egyptian obelisks among the various usual mortuary ornaments. The mausoleum suffered severe destruction in 410 AD during the 