The papal election held from 4 to 7 September 1159 following the death of Pope Adrian IV resulted in the election of two rival popes. A majority of the cardinals elected Cardinal Rolando of Siena as Pope Alexander III, but a minority refused to recognize him and elected their own candidate, Ottaviano de Monticelli, who took the name Victor IV, creating a schism that lasted until 1178.
The schism was a result of the growing tensions inside the Sacred College of Cardinals concerning the foreign policy of the Holy See. The Papal States in the 12th century were a buffer between the Holy Roman Empire and the Norman Kingdom of Sicily. After the Concordat of Worms in 1122, the Papacy allied with the Empire rather than with the Normans, but during the pontificate of Adrian IV (1154–59) this alliance broke up because Emperor Frederick I Barbarossa did not fulfil the terms of the treaty of Constance (1153) that obliged him to help the Papacy to restore its authority in Rome and in other territories controlled by the king of Sicily. In these circumstances Adrian IV decided to break the alliance with the Emperor and to make peace with William I of Sicily by signing the Treaty of Benevento (1156). In the following years there were growing tensions between the papacy and Emperor Frederick I Barbarossa (e.g. a dispute at the diet of Besançon in 1157). Frederick tried – with significant success – to strengthen his influence on the Church in Germany. The change of direction of the papal foreign policy resulted in the division of the Sacred College into supporters and opponents of the new policy, who were unable to achieve a compromise after the death of Adrian IV.