▁( t rib unic ian ▁power ) ▁from ▁the ▁Senate , ▁a ▁clear ▁sign ▁that ▁Dr us us ▁was ▁T iber ius ' ▁he ir . ▁However , ▁the ▁following ▁year ▁marked ▁a ▁turning ▁point ▁for ▁his ▁father ▁when ▁his ▁dispute ▁with ▁the ▁powerful ▁pra et or ian ▁pre fect ▁Lu cius ▁A el ius ▁Se jan us ▁reached ▁a ▁critical ▁point . ▁In ▁the ▁account ▁of ▁T ac it us , ▁Se jan us ▁began ▁plot ting ▁against ▁Dr us us ▁to ▁secure ▁his ▁position . ▁On ▁ 1 4 ▁September ▁ 2 3 ▁his ▁father ▁died ▁from ▁what ▁passed ▁as ▁natural ▁causes . ▁According ▁to ▁Cass ius ▁D io ▁and ▁T ac it us , ▁his ▁father ▁was ▁poison ed ▁by ▁his ▁wife ▁Liv illa ▁at ▁the ▁beh est ▁of ▁Se jan us . ▁The ▁exact ▁cause ▁of ▁the ▁fe ud ▁is ▁unknown . ▁▁ ▁His ▁father ' s ▁death ▁not ▁only ▁dev ast ated ▁T iber ius ▁but ▁also ▁challeng ed ▁the ▁future ▁of ▁the ▁princip ate . ▁T iber ius ▁still ▁trust ed ▁Se jan us ▁and ▁had ▁no ▁susp icion . ▁Since ▁Gem ell us ▁was ▁too ▁young , ▁T iber ius ▁adopted ▁his ▁grand children ▁by ▁German icus , ▁N ero ▁and ▁Dr us us , ▁and ▁recommended ▁them ▁to ▁the ▁Senate . ▁N ero ▁was ▁given ▁the ▁office ▁of ▁qu a est or ▁five ▁years ▁in ▁advance ▁and ▁was ▁married ▁to ▁Gem ell us ' ▁sister ▁Liv ia ▁to ▁combine ▁the ▁families ▁of ▁both ▁possible ▁success