Following the death of Pope Victor III on the 16th of September 1087, Otho de Lagery is elected Pope Urban II ⓘ on the 12th of March 1088. The election took place in Terracina, a town south of Rome, rather than in Rome itself, because the city was under the control of forces loyal to the antipope Clement III, who had been installed by the Holy Roman Emperor Henry IV during the Investiture Controversy which centered on who had the authority to appoint church officials.

It took Urban II several years to secure control over Rome, but he gradually gained support through diplomacy and reform efforts. He is most famous for launching the first crusade in 1095.