Kantakouzenos' relationship with the Turks had been based on personal friendship with their leaders, among them Orhan, to whom he had given his daughter in marriage.

However, now that the Turks have set up a base on European soil and have seen the possibilities of further conquest, such relationships are no longer practicable.

Kantakouzenos is anxious to continue his rule and in 1354 crowns his son, Matthew, co-emperor, but he soon falls from power, at least partially because of his cooperation with the Turks, and Europe begins to be aware of the extent of the Turkish danger.

In November of the same year, John V Palaiologos, encouraged by the anti-Kantakouzenist party, appeals to the Venetians for aid.

After a period of guerilla warfare waged by John V, the deposed emperor’s adherents successfully storm Constantinople in December, compel the abdication of Kantakouzenos, and installing the twenty-two-year-old John V as sole emperor.