@wandeljw,
wandeljw wrote:The last pope to resign did so because of a schism.
He actually (legally) didn't resign.
The last (and first and until today the only) Pope to resign was Coelestin V (Pietro del Murrone).
One of the two decrees he had ordered was the right of any pope to abdicate the papacy, a right that he himself exercised at the end of five months and eight days at Naples on 13 December 1294. He retired mainly, because his Latin wasn't good enough as well as he didn't have a great knowledge about the canon law.