The suicide of Nero on 9 June 68 brought the Julio @-@ Claudian dynasty to an end , leading to the chaotic Year of the Four Emperors , which saw the successive rise and fall of the emperors Galba , Otho and Vitellius , until the accession of Vespasian on 21 December 69 . Virtually nothing is known of Nerva 's whereabouts during 69 , but despite the fact that Otho was his brother @-@ in @-@ law , he appears to have been one of the earliest and strongest supporters of the Flavians .