Shortly after this an earthquake occurred in the Thracian Chersonese—not an unfrequent event there. It did great damage to many cities, among others to Gallipoli, the most important fortress on the European side of the Hellespont, and at no great distance from Tzympe. Its walls and ramparts were in great part tumbled down and destroyed, so that entrance to it was made easy. The Ottoman troops at the neighbouring Tzympe, under Solyman, when this opportunity was afforded to them of getting possession of such an important fortress, determined to avail themselves of it. The Greek garrison of Gallipoli, under the belief that the earthquake and the tumbling down of the walls indicated the Divine will, made no resistance, and the Ottomans established themselves there without opposition. Cantacuzene complained of this to Orchan as a gross breach of their treaty, and demanded that Gallipoli should be restored to him. He offered also to pay a fair price for Tzympe. Orchan, though willing enough to take money for Tzympe, refused point-blank to give up Gallipoli. “God,” he said, “having manifested His will in my favour by causing the ramparts to fall, my troops have taken possession of the city, penetrated with thanks to Allah.” It will be seen that Greeks and Turks took the same view of the Divine intervention, the one to excuse their failure to defend the fortress, the other to justify their seizure of it. This action of Orchan roused great indignation at Constantinople. Cantacuzene now began to see how grave an error he had committed when inviting the Turks into Europe. Public opinion compelled him to declare war against Orchan. He appealed to the Czars of Serbia and Bulgaria to assist him in driving the Ottomans back to Asia. They flatly refused to do so. The Czar of Bulgaria replied: “Three years ago I remonstrated with you for your unholy alliance with the Turks. Now that the storm has burst, let the Byzantines weather it. If the Turks come against me we shall know how to defend ourselves”—a very unfortunate prediction as events ultimately proved! The whole course of history might have been altered if these two Balkan States had joined with the Byzantines in preventing this lodgment of the Turks in Europe. Want of union of the Christian Powers was then, as on many other later occasions, mainly responsible for the extension of the Ottoman Empire in that continent.