Sedevacantism is the position, held by a small group of Traditionalist Catholics, that the person in the papal see right now is not truly pope and that, for lack of a good pope, the see has been empty since the death of Pope Pius XII in 1958. A tiny number of these people claim the vacancy actually goes back to the death of Pope Pius X in 1914, among other little-known positions.
- European Sodalitium Pianum Archived 2014-07-09 at the Wayback Machine
- Sedevacantist European Seminary Archived 2014-07-09 at the Wayback Machine
- Sedevacantism Reconsidered Archived 2013-11-16 at the Wayback Machine
- Evidence of sedevacantism
- The Aquinas site. Sedevacantist.com. Archived 2014-06-21 at the Wayback Machine