In the attacks by Stephen, the kral of Serbia, who had taken the title of emperor of the Serbians and the Greeks, or emperor of Serbia and Romania--for both forms are used--Orchan once more sent troops to aid his father-in-law. In the struggles which took place at this time between the Genoese and the Venetians, Orchan aided the first. When the emperor wished to employ both, he was obliged to concede to the Turks a stronghold on the Thracian Chersonese. They, however, always proved to be dangerous allies, and the inhabitants of the whole northern coast of the Marmora were so harassed by them that great numbers deserted their farms and fled to the capital or elsewhere. [Sidenote: Angora taken (1354).] It was in 1355 that Cantacuzenus left the government in the hands of John. His policy and his influence had been directed towards coming to an agreement with the leading group of Turks--that, namely, ruled over by his son-in-law. Almost the last act before his withdrawal was to persuade Orchan and his son, Suliman, to give up the cities in Thrace which the Turks had occupied, on his behalf, during the struggle with John.[88] Orchan, on his part, was to all appearances disposed, on the retirement of Cantacuzenus, to be on friendly terms with John, and, in consequence, each party assumed the attitude of an ally. It may be suggested that if a policy of friendliness had been continued, the Turks might have been content with their territory in Asia Minor. But such a solution was not possible. The Turkish nomad warriors, to whom the cultivation of the soil was distasteful, required new lands to roam over, and wanted new territories to plunder. The arable lands, which had supported large populations, were too small for nomad shepherds, and the latter were always being pressed forward to the north and west by a constant stream of immigrants behind them. Indeed, in the year when Cantacuzenus abdicated, Suliman, the son of Orchan, had to lead his armies and defend his territories against a newly arrived horde of Tartars in the north-east of Asia Minor. His successful defence was, at the same time, one more blow against the empire, for in this campaign he succeeded in capturing the important stronghold of Angora, which commanded the great highroad to Persia.