Dionysius now proceeded to Damascus, where he was honourably received by the governor, Barhebræus acting as interpreter. In these negotiations, however, Dionysius fell into a stupid blunder, exhibiting the letter of a Mongol magnate which had been intended for his supporters in Melatia. This caused great offence, for the Tartars were regarded as mortal enemies by the Moslems. It was only with great trouble, and through the intervention of Ibn Amíd (Elmacinus), the well-known Coptic author, that Dionysius at last succeeded in obtaining his diploma of confirmation on payment of a large bribe.
Barhebræus was soon afterwards named by Dionysius to be bishop of Aleppo; but on the installation there of a partisan of John’s, he withdrew, along with his father, to the Barsaumá monastery, where his patriarch was. John betook himself to the Armenian king of Sís, while Dionysius received recognition almost everywhere. Barhebræus soon again took up his abode in Aleppo. When the Mongols, who in the meantime had taken Bagdad (January 1258), entered Syria he wished to go to meet them, plainly with the object of securing mild treatment for the Christians. The idea was not unreasonable, for their common antipathy to Islam readily predisposed the Mongol chiefs in favour of the Christians, who, moreover, sought only toleration, and did not fight for sovereignty like the Moslems. Some of those wild Tartars had, moreover, been baptized, for the Nestorians had successful missions among the Turkish tribes. Dokuz Khatun herself, a wife of the sovereign Hulagu, who formerly had been one of the wives of his father Tuli, and who in accordance with Mongol custom had passed with the rest of the inheritance to the son, was a Christian, and did much for the protection and advantage of her co-religionists. But the attempt in this instance was unsuccessful. Barhebræus was detained at Kalat-Nejm, one of the Euphrates ferries; and Hulagu meanwhile coming to Aleppo, occupied the town, and inflicted on Moslems and Christians alike all the horrors of a sack (January 1260).
Dionysius compromised himself seriously. That he obtained letters of confirmation from the Mongol sovereign (1259) was not amiss, especially as the Seljuks and the Armenian Christian king had equally acknowledged the Tartar as their overlord. But it was a scandal that he connived at the robberies of the Christian subjects of the St. Barsaumá monastery, who had broken loose from all restraint in this period of general corruption and dissoluteness. And he finally lost the last shred of reputation by procuring the assassination of a cousin who had been a great trouble to him, and of his cousin’s brother, only a few days after a reconciliation had taken place; even the _chronique scandaleuse_ of the history of the Jacobites supplied no parallel to such conduct. To escape the consequences of his deed the patriarch again went to Hulagu, and after overcoming many obstacles was lucky enough to secure his special protection, so that he was able to lord it more tyrannically than ever. And now the monastery of St. Barsaumá witnessed an unheard-of scene; the murderous patriarch was assassinated before the altar as he was holding a night service (17th-18th February) by a monk, a deacon, and a layman, nephew of one of the abbats. The assassins threw the “disciple” of the patriarch, who had been his instrument in the murder of his cousin, down the rock.