Pope Innocent II (died September 24, 1143), born Gregorio Papareschi, was Pope from 1130 to 1143, and was probably one of the clergy in personal attendance on the antipope Clement III (Guibert of Ravenna).
In 1130, as Pope Honorius II lay dying, the cardinals decided to entrust the election to a commission of eight men, led by papal chancellor Haimeric, who had his candidate Cardinal Gregory Papareschi hastily elected as Pope Innocent II. He was consecrated on February 14, the day after Honorius' death. The other cardinals announced that Innocent had not been canonically elected and chose Cardinal Pietro Pierleoni, a Roman whose family were the enemy of Haimeric's supporters, the Frangipani, who took the name Pope Anacletus II. Anacletus' mixed group of supporters were powerful enough to take control of Rome while Innocent was forced to flee North; based on a simple majority of the entire college of cardinals, Anacletus was the canonically elected Pope, and Innocent was the anti-Pope. However, the majority of the cardinal bishops supported Innocent, which according to the legislation of Pope Nicholas II (in the famous decree of 1059) pre-empted the choice of the majority of the cardinal priests and cardinal deacons. This rule was changed by the II Lateran Council in 1139.
Anacletus had control of Rome, so Innocent II took ship for Pisa, and thence sailed by Genoa to France, where the influence of Bernard of Clairvaux readily secured his cordial recognition by the clergy and the court; in October of the same year he was duly acknowledged by Lothar III of Germany and his bishops at the synod of Würzburg. In January 1131, he had also a favourable interview with Henry I of England (1100–35); and in August 1132 Lothar III undertook an expedition to Italy for the double purpose of setting aside Anacletus as antipope and of being crowned by Innocent. The coronation ultimately took place in the Lateran church (June 4, 1133), but otherwise the expedition proved abortive. A second expedition by Lothar III in 1136 was not more decisive in its results, and the protracted struggle between the rival pontiffs was terminated only by the death of Anacletus II on January 25, 1138.
In 1143, as the pope lay dying, the Commune of Rome, to resist papal power, began delibrations that officially reinstated the Roman Senate the following year. The Pope was interred in a porphyry sarcophagus that contemporary tradition asserted had been the Emperor Hadrian's.