On 12 February 1612 Karmah was consecrated metropolitan bishop of Aleppo by Patriarch Athanasius II Dabbas, and he took the name of the saint of that day, ‘'Meletios'’.
One of his aims as metropolitan was to increase the literacy and the education of his flock and his presbyter, which needed liturgical and religious books in Arabic.
In 1628 he took part to the Synod of Ras-Baalbek where, along with all the other Melkite bishops, deposed Cyrill declaring Ignatius III to be the sole patriarch.
[3] Because of his friendly relations with the Western missionaries he had in the previous years, his first decision as Patriarch was to send a delegation to Rome to renew the union with the Catholic Church set forth in the Council of Florence.
In the meantime his delegation arrived to Rome and obtained a positive response from the Propaganda Fide, he died in Damascus on 1 January 1635, probably poisoned because his will to proceed with a union with the Catholic Church.