Question: The papal election of 1159 followed the death of which pope, who ruled from 1154 until 1159?
Sentence (from "Papal election, 1277"): Because John XXI had revoked "Ubi periculum", the papal bull of Pope Gregory X establishing the papal conclave, with his own bull "Licet felicis recordationis", the cardinal electors were able to take their time.
Relevant evidence: No