Al-Maʼmūn himself was very zealous in his efforts to spread the faith of Islam, and sent invitations to unbelievers even in the most distant parts of his dominions, such as Transoxania and Farghānah. [211] At the same time he did not abuse his royal power, by attempting to force his own faith upon others: when a certain Yazdānbakht, a leader of the Manichæan sect, came on a visit to Baghdād [212] and held a disputation with the Muslim theologians, in which he was utterly silenced, the caliph tried to induce him to embrace Islam. But Yazdānbakht refused, saying, “Commander of the faithful, your advice is heard and your words have been listened to; but you are one of those who do not force men to abandon their religion.” So far from resenting the ill-success of his efforts, the caliph furnished him with a bodyguard, that he might not be exposed to insult from the fanatical populace. [213] Some scanty references are made by Christian historians to cases of ecclesiastical dignitaries who became Muhammadans, e.g. George, Bishop of Baḥrayn, about the middle of the ninth century, having been deposed from his office for some ecclesiastical offence, exchanged the Christian faith for that of Islam, [214] and the conversion of a brother of Gabriel, metropolitan of Fārs about the middle of the tenth century, only receives mention because the fact of his having become a Muslim was alleged as disqualifying Gabriel for election to the patriarchate of the Nestorian church. [215] In the early part of the same century, Theodore, the Nestorian Bishop of Beth Garmai, became a Muslim, and there is no mention of any force or compulsion by the ecclesiastical historian [216] who records the fact, as there undoubtedly would have been, had such existed. Some years later (between A.D. 962 and 979), Philoxenos, a Jacobite Bishop of Ādharbayjān, also became a Muslim, [217] and in the following century, in 1016, Ignatius, [218] the Jacobite Metropolitan of Takrīt, who had held this office for twenty-five years, set out for Baghdād and embraced Islam in the presence of the caliph al-Qādir, taking the name of Abū Muslim. [219] It would be exceedingly interesting if an Apologia pro Vita Sua had survived to reveal to us the religious development that took place in the mind of either of these converts. The Christian chronicler hints at immorality in the last three cases, but such an accusation uncorroborated by any further evidence is open to suspicion, [220] much as it would be if brought forward by a Roman Catholic when recording the conversion of a priest of his own communion to the Protestant faith. It is doubtless owing to their exalted position in the Church that the conversion of these prominent ecclesiastics of two hostile Christian sects has been handed down to us, while that of more obscure individuals has not been recorded. As Barhebræus brings his ecclesiastical chronicle nearer to his own time, he gives fuller details of the career of such converts, e.g.