Frankish royal family which governed Antioch. He was educated in Antioch and the monastery of Saint Maron studying mathematics, sciences, philosophy, theology, linguistics and scripture. He became a monk at the monastery of Saint Maron, adding the name Maron to this own.
John studied Greek and patrology in Constantinople. Returning to Saint Maron's, he wrote on such diverse topics as teaching, rhetoric, the sacraments, management of Church property, legislative techniques, and liturgy. He composed the Eucharistic Prayer which still bears his name. Noted teacher and preacher, he explained Catholic dogma to the Council of Chalcedon, wrote a series of letters to the faithful against Monophysitism and Monothelitism, and then travelled Syria to explain the heresy.
Bishop in 676, assigned to Mount Lebanon with a mission to oppose heresies, keep the Maronites united with Rome, and support the faithful in an area being invaded by Arabs. He travelled extensively in the areas involved in combat, preaching, conducting Mass, tending to the sick, and sheltering the homeless. It was during this terrible period that he was given the gift of healing, curing many praying over them.
The Maronites made up the bulk of the Maradite army, the so-called "Brass Wall" that shielded Constantinople and the Byzantine Empire from Arab expansion. In 685 the Maradites used their power and importance to choose John Maron, one of their own, as Patriarch of Antioch and all the East. John received the approval of Pope Sergius I, and became the first Maronite Patriarch of the oldest see in Christianity.
The Byzantine emperor Justinian II feared the growing power of the Maradite army, and was angered that his approval had not been sought for the appointment of John as Patriarch. He sent his army to defeat the Maradites and capture John. They managed to win battles against the Maradites, overrun Antioch, and destroy the monastery there, killing 500 monks in the process. John, however, escaped to Lebanon. When Justinian's army followed, the Maradites, under the leadership of John's nephew Ibrahim, defeated them decisively, sending them home empty-handed. John then founded the monastery of Reesh Moran (head of our Lord) in Kefer Hay, Lebanon, and moved his see to Mount Lebanon. The Maradites sealed themselves off from the outside, and founded their own national and religious identity, though still part of the Catholic Church, with John seen as one of their great founders.