Celestine II

Guido of Città di Castello had studied under Peter Abelard and never disowned him, which took some nerve: Bernard of Clairvaux had secured Abelard's condemnation in 1140, and Guido kept the master's books and defended his memory. He was made a cardinal by Honorius II, stayed loyal to Innocent II through the schism, and was elected in September 1143 as the compromise the exhausted curia needed.

He had five months and one substantial act. Innocent II had laid an interdict on the lands of Louis VII of France, in a quarrel over the archbishopric of Bourges that had escalated into open war and the burning of a church full of villagers at Vitry. Celestine lifted it, and began repairing relations with a king whose support the papacy would shortly need.

The larger problem he could do nothing about. Rome had declared itself a commune in 1143, revived the Senate on the Capitol, and repudiated papal government of the city altogether. Celestine died in March 1144 with the revolt unresolved, and it would kill the next pope outright.