Cantacuzenos, feeling the precariousness of his position at Constantinople just at the moment when he thought he had triumphed over every obstacle to his ambition, bitterly reproached Orkhan for not having kept faith with him. He offered to buy back Tzympe for ten thousand ducats, and asked Orkhan to order the Osmanlis to leave Gallipoli. Orkhan accepted the ransom for Tzympe, knowing well that he could reoccupy this fortress when he wanted to.[230] As for Gallipoli, he declared that he could not give back what God had given him. Was it not the will of God rather than force of arms that had opened the gates of Gallipoli to him? Cantacuzenos sought an interview with his son-in-law, for he thought that gold might induce the Osmanlis to withdraw. A meeting was arranged in the Gulf of Nicomedia. When the emperor arrived at the rendezvous, a messenger from Orkhan reported that his master was ill and could not come.[231] No way was left open for further negotiations. The rupture was complete. After his return to Constantinople, Cantacuzenos sent envoys to the Serbians and to the Bulgarians to urge a defensive alliance of the Balkan Christians. They answered, ‘Defend yourself as best you can.’ A second embassy met with the response from Czar Alexander: ‘Three years ago I remonstrated with you for your unholy alliances with the Turks. Now that the storm has broken, let the Byzantines weather it. If the Turks come against us, we shall know how to defend ourselves.’[232] The indignation of the Greeks against the man who had sacrificed them to his inordinate ambition reached the breaking-point in November 1354. The inhabitants of Constantinople declared for John Palaeologos. Cantacuzenos was forced to barricade himself in his palace. Protected by Catalans and other mercenaries, he tried to temporize. He offered to abdicate if Matthew were allowed to retain the title of emperor with the governorship of Adrianople and the Rhodope district. Encouraged by a lull in the storm of popular feeling, he had the audacity to make an ‘appeal to patriotism’, as he himself put it. He urged the people to support him in an expedition to retake the provinces conquered by the Serbians and the Osmanlis. This exhibition of effrontery was greeted with cries of scorn. Cantacuzenos was publicly accused of wishing to deliver Constantinople to Orkhan. A second revolution forced his abdication. He became a monk. Irene took the veil.[233] John Palaeologos returned from exile, and restored Callixtus to the patriarchal throne. It took several years of fighting and negotiating to compel Matthew’s abdication. Not until 1358 did John V become undisputed ruler of the remnant of the empire in Macedonia and Thrace.[234] But the mischief was done. The Osmanlis had put their foot as settlers on European soil.