John V was Greek Orthodox Patriarch of Jerusalem (706–735).
[1] John V of Jerusalem was the patriarch of Jerusalem during the iconoclastic struggles under the Byzantine emperor Leo III the Isaurian as well as the time of persecution in Palestine and Syria under Muslim rulers.
Patriarch John also supported John in his efforts against emperor Leo and the iconoclasts, including writing a number of tracts against iconoclasm.
During his patriarchate, John had to contend with the Umayyad caliph Omar II.
Read Umar’s Assurance (Wikipedia) which gives full protection to Christians and their places of worship and property.