Antipope Victor IV

Victor IV (born Octavian or Octavianus: Ottaviano dei Crescenzi Ottaviani di Monticelli) (1095 – 20 April 1164) was elected as a Ghibelline antipope in 1159, following the death of Pope Adrian IV and the election of Alexander III. His election was supported by Emperor Frederick Barbarossa. He took the name Victor IV, not acknowledging Antipope Victor IV of 1138, whose holding of the papal office was deemed illegitimate.

Source: Wikipedia — https://en.wikipedia.org/wiki/Antipope_Victor_IV_(1159%E2%80%931164)