In the course of the following year, 1351, Cantacuzenus returned to attack the Genoese, with the aid of their mortal enemies, the Venetians. As he seems to have intended from the beginning, he left John in Thessalonica, with the young Empress Helena, but he was alarmed and surprised in the following year to hear that the young Emperor was corresponding with the Kral of Servia. Gregoras says that, under pressure from the Kral, John engaged to divorce Helena and marry the Kral’s sister. When Cantacuzenus heard this, he went with Anna into the venerable chapel of the Virgin at Blachernæ, and swore that he would resign the crown to John if he would abandon the Kral and bring Helena to Constantinople. The oath was committed to writing, and Anna herself conveyed it to Thessalonica. It says something for the singular character of Cantacuzenus that they implicitly trusted his oath, and the young couple returned to the capital. After a few weeks, however, John distrusted his colleague and returned to Thrace with Helena. Her father seems to have tried to detach her from John, but she protested, Gregoras says, that she would “rather die with John than live with her parents.” In return, apparently, for this fidelity John made a new compact with the Kral and received an army without abandoning his wife. He at once attacked Matthew, the Emperor’s son, in Adrianople, and let civil war loose once more upon the surviving province of the Empire; if, indeed, one can call “civil war” a contest in which hardly a single Greek soldier was enlisted. For the sake of rival Byzantine ambitions Turk fought Servian and Bulgarian on land, and Venetian fought Genoese at sea, and the decrepit Empire sank into its last stage. The Empress Irene once more endeavoured to make peace between the combatants. She went to Thrace and laid before the young Emperor a politic and admirable scheme--admirable, at least, on the supposition that Cantacuzenus is lying when he declares that he and Irene were minded to enter a monastery, which would have been the best solution. On the other hand, John does not command our sympathy and respect. In three years’ time he would be twenty-five, and might have laid claim to the throne with perfect right and more success. Irene proposed that John and Matthew should divide the western territory, and that Cantacuzenus should hold the remainder until his death. John refused the terms, Irene returned to Court, and the Turks and Servians flew at each other.