Gelasius II had a turbulent one year term. He was elected unanimously, and began to set up institutional structures around the papacy - clerks, offices, things like that - but was pulled into the political struggles with HRE Henry V. He was arrested by the emperors emissaries, and then freed by a popular uprising of the local Romans. Then Henry chased him from the city and installed an anti-pope; Gelasius fled to his hometown of Gaeta, took orders as a priest and promptly excommunicated Henry. He returned to Rome under french protection a few months later, but was chased back into France, where he died.

Whew! That's a busy year for a pope.