Fortune again favoured the Osmanlis. Czar Alexander died in 1365,[310] leaving three heirs. To John Sisman fell middle and southern Bulgaria from the Danube to the Rhodope Mountains and the Bulgarian pretensions in Thrace. Old Tirnovo was his capital. Stracimir inherited western Bulgaria, with Widin for capital, and the Bulgarian pretensions to the valley of the Vardar and western Macedonia. (The Bulgarian remnant of eastern Macedonia was in the hands of an independent Bulgarian prince, Constantine, whose stronghold was Kustendil.) Dobrotich became master of the Dobrudja and the upper Black Sea coast, where Bulgarian, Cuman and Alan lived together with hardly any distinguishing characteristics.
The division of Bulgaria, at the moment when union was essential, proved fatal. The sons of Alexander never joined to face the common danger. So marked was the division of Alexander’s kingdom that thirty years after the conquest the conquered territories were known as ‘the three Bulgarias’.[311]
Stracimir, jealous because Sisman seemed to have received the lion’s share of Alexander’s inheritance, did not hesitate to make overtures to Murad, offering to co-operate with the Osmanlis against his brother and to share the portion of Sisman with them.[312] Before any agreement could be made, however, Stracimir found himself face to face with a terrible danger in the west, which soon caused him to forget both Sisman and Murad. Louis of Hungary had interpreted his crusader’s commission as an authorization to ‘make war against the heretics’. It was a pretext to get possession of Widin, which was essential to his ambitious project of adding Serbia to his kingdom. He attacked the Bulgarians on the ground that they were enemies of the Church and must be forced to acknowledge the supremacy of Rome. Widin was captured and Stracimir imprisoned.[313] Stracimir’s dominions were flooded with Franciscan missionaries, who were backed by a brutal soldiery in their proselytizing efforts.[314] Two hundred thousand Bulgarians abjured the orthodox heresy, and were re-baptized in the Latin rite. This forcible conversion, which was purely a political matter, was as objectionable to the Bulgarians as to the Cretans. They hated ‘with a perfect hatred’ the Franciscans whom Pope Urban had sent, and the cause for which they stood.
At the first opportunity, the Bulgarians of the west called in Sisman and Vadislav of Wallachia. The Hungarians were driven out of Widin and the Franciscans in the city massacred.[315] Louis was powerful enough to wreak terrible vengeance. In 1370, Widin fell once more into his hands. The Bulgarians of the western Balkans were subjected to such a relentless persecution that they welcomed the Moslem conquest to secure freedom of worship. Urban had incited Louis to this war, and had congratulated him upon his laudable zeal in converting the heretics.[316]
We have already spoken of the punishment that came to Sisman as a result of the detention of John Palaeologos. The Italian crusaders on the Black Sea coast were as powerful an aid to Murad’s empire-building as were the Hungarian crusaders on the western frontier. The successors of Louis reaped the bitter fruits of his insane policy. Louis and Amadeo of Savoy contributed in no little measure to make possible the conquests of Murad. When Amadeo withdrew from Bulgaria, he left the cities he had captured to the Greeks. Sisman was compelled to expend his energy in recapturing them. But Murad had already anticipated him in the important fortress of Sozopolis, which commanded the entrance to the port of Burgas.[317]
Shortly after the Ottoman occupation of Sozopolis, the Bulgarians were everywhere dispossessed in Thrace, and the capture of Yamboli[318] forced Sisman to follow the example of John Palaeologos. He became a vassal of Murad. His sister Mara entered Murad’s harem, but with the stipulation that she be allowed to retain her Christian faith.
Murad gladly gave his new ally and brother-in-law a strong Ottoman army to co-operate in the attack upon the Hungarians. The Osmanlis helped in driving Louis out of Widin. Sisman, like Cantacuzenos, first guided the Osmanlis through the heart of his country. It was under the leadership of Sisman that they saw the Danube, their river of destiny. When Sisman, even with the help of the Osmanlis and Wallachians, could not gain possession of Stracimir’s inheritance, he returned to Tirnovo. There he learned that Lalashahin was planning an expedition westward, which seemed to be intended against Sofia.
Sisman now realized that his position was critical and that the fate of Bulgaria was at stake. In the early spring of 1371, he hurried into the Rilo Mountains and sent out an appeal to the Serbian kral who was at that time ruling in eastern Macedonia. Then he went to the relief of Ishtiman, which was already menaced by the Osmanlis. Failing in this effort, Sisman fell back to Samakov, where he was joined by the Serbians. Lalashahin led his army from Ishtiman into the valley of the Isker. The two krals joined battle with him in the plain of Samakov. The Ottoman victory was decisive.[319] The Serbians and Bulgarians fled into the recesses of Musalla, the highest mountain in the Balkan peninsula, and of Popova Shapka. Sisman disappeared after the battle.[320] The way to Sofia was open. All Bulgaria lay at the feet of the conqueror. It is from the battle of Samakov that we must date the destruction of an independent Bulgaria.
But Murad was not yet ready to follow up this decisive victory. The only immediate result of the battle of Samakov was the submission of Constantine, Bulgarian prince of Kustendil, in the upper valley of the Struma. After the fall of Samakov, his position was untenable. Constantine hurried to Murad’s camp, and did homage to the conqueror. Murad gave back to him as vassal his principality.[321] With the wisdom that marked every successive step of his progress in Europe, Murad refrained from advancing beyond Samakov. He ordered Lalashahin to lead the army into Macedonia, and to join Evrenos in the advance towards the Vardar.