Leontius was elected to the patriarchal see in 911 after Patr. Sergius II of Jerusalem reposed. In 923, the patriarchate was plagued by Muslim riots when they were angered by several victories by the Byzantine armies in the Arab–Byzantine wars. The rioters took special revenge on the Christians in Ashkelon and Caesarea where all the churches were destroyed. The Church eventually received permission from Caliph al-Muqtadir to rebuild the churches.