Tiberius, perhaps sensitive to this ambition, rejected Sejanus's initial proposal to marry Livilla, Germanicus' sister and the widow of Tiberius' son Drusus the Younger, who had since died, in AD 25, but later had withdrawn his objections so that, in AD 30, Sejanus was betrothed to Julia Livia, daughter of Livilla and Drusus the Younger. Sejanus' family connection to the Imperial house was now imminent, and in AD 31 Sejanus held the Consulship with the emperor as his colleague, an honour Tiberius reserved only for heirs to the throne. When he was summoned to a meeting of the Senate later that year on 18 October AD 31, he probably expected to receive a share of the tribunician power. Instead, however, Tiberius' letter to the Senate, completely unexpectedly, requested the destruction of Sejanus and his faction. A purge followed, in which Sejanus and his most prominent supporters were killed. With Drusus dead and having had Germanicus' elder two sons Nero and Drusus convicted of treason and killed, along with their mother Agrippina, Tiberius appointed Caligula, Germanicus' youngest son, and Tiberius Gemellus, the son of Drusus the Younger and grandson of Tiberius, co-heirs. Drusus III's wife Aemilia Lepida was later forced to commit suicide after being accused of adultery.