7 antipopes

An Antipope is a person who opposes a legitimately elected or sitting Pope and makes a significantly accepted competing claim to be the Pope

1. Novatian: 251-258 CE
2. John VIII: 844 CE
3. Boniface VII: 974, 984-985 CE
4. Honorius II: 1061-1064 CE
5. Sylvester IV: 1105-1111 CE
6. Alexander V: 1409-1410 CE
7. Felix V: 1439-1449 CE