Audita tremendi was a papal bull issued by Pope Gregory VIII on October 29, 1187, calling for the Third Crusade. It was issued just days after Gregory had succeeded Urban III as pope, in response to the defeat of the Kingdom of Jerusalem at the Battle of Hattin on July 4 of 1187. Gregory travelled to Pisa in order to end Pisan hostilities with Genoa so that both seaports and naval fleets could join together for the crusade.