Cantacuzene was soon to reap the just reward for his treachery to his country. So far everything had gone well with him. He had ousted the Palæologi from the throne, of which, it must be admitted, they were quite unworthy. He had proclaimed his son Matthew as co-Emperor with himself. But when the full effect of his policy of inviting the Turks into Europe was understood there was a revulsion of feeling against him at Constantinople. The Greek Patriarch refused to crown Matthew. A revolution took place in the city. Cantacuzene found himself without friends. He was everywhere accused of having betrayed the Empire to the Turks. He was compelled to abdicate. He became a monk and retired to a monastery in Greece. He spent the remaining thirty years of his life in seclusion there, and in writing a history of his times, which, though very unreliable, tells enough of his own misdeeds to justify the conclusion that, by inviting the Ottomans into Europe, he proved to be a traitor to his country. The Empress Irene, his wife, became a nun. John Palæologus was recalled by the people of Constantinople, and, after defeating Matthew, not without difficulty, was established there as sole Emperor. His reign lasted for fifty years, a period full of misfortune for the Empire. He was no more able to compel or induce the Turks to evacuate Europe and return to Asia than his father-in-law. The twenty thousand soldiers who had been invited to Europe by Cantacuzene remained there as enemies of the State they had come to assist. Under the command of Solyman, they advanced into Thrace and captured Tchorlu, within a few miles of Constantinople. Though the occupation of this city and of Demotika was only temporary, the Ottomans firmly established themselves in the southern part of Thrace. The Emperor John was eventually compelled to sign a treaty with Orchan, which recognized these Ottoman conquests in Thrace. Thenceforth the Byzantine Empire became subservient to, and almost the vassal of, the Ottoman Sultan. Solyman brought over from Asia many colonies of Turks and settled them in the Thracian Chersonese and other parts of Thrace.