Augustus had died without having removed Postumus from Planasia and without including him in his will, regardless of the emperor's supposed visit the previous year.

Postumus is executed by his guards around the time of Augustus' death, with some accounts contradicting whether it happened before or after Augustus’ demise.

Accounts are also inconsistent on who ordered the death and these exist almost from the start, when Tiberius immediately and publicly disavows the act upon being notified of it (Tacitus, Ann. 1.5).

Some suggested that Augustus may have ordered the execution, while others place the blame on either Tiberius or Livia (with or possibly without Tiberius's knowledge) (Suetonius, Lives, Tiberius 22), taking advantage of the confusing initial political situation upon Augustus' death.