Even after the Turks had beaten the Serbs severely, Stefan Tvrtko, King of Bosnia, seems only to have regarded this as an advantage to himself. He continued extending his realm; had himself crowned "King of Bosnia, Serbia and the coastland" in 1375, and was then the most powerful of the Balkan rulers. As an ally of King Lazar, who ruled over a much reduced Serbia, he, too, sent an army to Kosovo when, far too late, the Balkan people at last united against the Turk. But they lost the day. Union Was impossible to them, and a large part of the Serb Army deserted to the enemy.
Even then the Balkan princelings failed to recognize their danger. Tvrtko, still bent on extending his realm, Instead of opposing the Turks, who did not follow up their victory, gave all his energies to waging war against the Croats and Dalmatians, who at that time were under the King of Hungary. Tvrtko died in 1391, bequeathing a big Bosnia to his heir. But all mediaeval Balkan States were big only during the lifetime of their creator. Tvrtko's brother soon lost the newly acquired Croatian and Dalmatian districts, and Bosnia was further weakened by the breaking off of what is now known as the Herzegovina. It had for long had its own chiefs. One stronger than usual now arose, Sandalj Ranitch. The Turk was almost at the gate, but Sandalj's only object was to make himself a state independent of Bosnia. Kosovo had indeed taught the South Slavs nothing.
The advancing Turk began raiding Bosnia and employed Serbian troops. The Ragusa archives record: "In January 1398, the son of Bajazet, with a great number of Turks and Slavs, entered Bosnia." Stefan Ostoja was now King of Bosnia, but he too seems to have been more intent upon annexing Ragusa than in organizing defence against the Turk. Nor can we stop to unravel the complicated series of quarrels of one Slav prince with another, of their intrigues with Venice, with Hungary, with Ragusa, each playing for his own hand, though the Turks were now established as near as Uskub, and in 1415 invaded Bosnia for the third time. Sigismund, King of Hungary, alone of the neighbouring princes, realized the gravity of the situation and sent an army against the Turks, only to find that the Herzegovina sided with the Turks against him. As a result, we learn from the Ragusa archives, "the whole of Bosnia is laid waste and the barons are preparing to exterminate each other."
Venice meanwhile crept down the coast and occupied much of Dalmatia, while the South Slavs fought each other.
Nationality is the craze of to-day. Religion, in the Middle Ages, played a similar part. Catholic, Orthodox, and Bogumil, hated each other more than they hated the less known Turk. Each was willing to use him against the other.
People of the same race and language then fought each other because they differed about religion. To-day, even holding the same religious views, they fight in the sacred name of nationality. But then, as now, there were a few people who recognized the folly of the fashionable differences. At the Council of Basel in 1431 an effort was made to induce the Balkan chiefs, Catholic, Orthodox and even Bogumil, to send delegates to Basel with a view to ending religious strife and opposing a united front to the Turk.
It was vain. The King of Bosnia, and Stefan, Despot of Serbia, declared war on each other and fought for several years. And Sandalj, Lord of the Herzegovina, sided with the Serbs and bought of the Sultan the right to take Bosnia. They failed to do so, but their efforts certainly helped the final destruction of Slav independence.
Sandalj's successor, Stefan Kosatch, assumed the title Duke of Sava (whence "Herzegovina" the Duchy), became Bogumil and consequently fought both the Orthodox of Serbia and the Catholics of Ragusa. And ever the Turk advanced slowly and always found a Slav chief ready to side with him against a neighbour. At Fotcha, in the Herzegovina, I bought a bracelet of a silversmith, who related that his ancestor was the man who had guided the Turks into the district.
Constantinople fell in 1453, and left the Sultan free to complete the conquest of the Balkans. The Hungarians, led by the great Hunyadi, opposed him. But the Orthodox Serbs, led by their Despot George Brankovitch, whose ancestor had deserted to the Turks at Kosovo, hated Catholicism more than Islam, and sided with the Turk against Hunyadi.
The end soon came. The last King of Bosnia, Stefan Tomashovitch, a Catholic, asked help of the Pope, and endeavoured to raise troops among the Catholics of Dalmatia and Croatia. This enraged his Bogumil subjects, who preferred the Turks. The Sultan's army met little resistance; Stefan was taken prisoner and beheaded by the Turks in 1463, and soon all Bosnia was included in the Turkish Empire. As in other Balkan lands, the rights of the Christians were recognized. The Franciscans were appointed as their spiritual head, and several Franciscan monasteries date from these early days.