By AD 65, senators complained that they had no power left and this led to the Pisonian conspiracy, led by Gaius Calpurnius Piso, an adoptive descendant of Triumvir Marcus Licinius Crassus, grandson of Gnaeus Calpurnius Piso, a governor of Syria who committed suicide after being accused of killing Germanicus, and first husband of Livia Orestilla, Caligula's second wife. The conspiracy failed and its members were executed. Vacancies after the conspiracy allowed Nymphidius Sabinus, a grandson of former imperial freedman Gaius Julius Callistus, who claimed to be an illegitimate son of Caligula, to rise in the Praetorian Guard.