Tags: Pope.
Antipope Callixtus III or Callistus III (died before October 19 1183) was Antipope from September 1168 to 29 August 1178.His real name was Giovanni Abbot of Struma. He was a strong and early supporter of Frederick Barbarossa and also supported Antipope Victor IV who made him a cardinal-bishop of Albano.He was named successor to Antipope Paschal III by a small number of schismatic cardinals.