1.The Fortress at the Crossing
Nikopol stands on the south bank of the Danube, opposite the mouth of the Olt, and together with Svishtov guards one of the convenient crossing points of the river. At the end of the fourteenth century, when the Ottomans already held Thrace and Sredets, the Danube fortresses became the last line of the tsardom of Tarnovo and its bridge to Hungary and Wallachia — from where the Bulgarians still hoped for help.
2.The Surrender of 1388
In 1388 the grand vizier Ali Pasha punished Ivan Shishman for refusing to send help to Sultan Murad. His army crossed the Balkan range, took Shumen and Provadia, then turned to the Danube, took Svishtov and besieged Nikopol, where the tsar was shut up with one of his sons. The fortress was not taken by storm, but in the words of the Ottoman chronicler Neşri "Sosmanoz" took fright, hung a shroud around his neck and came out with his son to fall at the pasha's feet.
The price of peace was the surrender of Silistra. Once Ali Pasha withdrew, Ivan Shishman tried to put off keeping his promise and even to fortify the city — which brought a new siege of Nikopol and the final loss of Drastar. The chronicler Saadeddin tells a smoother version — that Murad came before Nikopol in person and left the fortress to the tsar in exchange for Silistra — but historians do not accept it as reliable.
3.The Tsar's Last Refuge (1393–1395)
When Bayezid besieged Tarnovo in the summer of 1393, Ivan Shishman was not in the capital — he had already settled at Nikopol, probably hoping for help from King Sigismund of Hungary, with whom he may have been negotiating a secret alliance. After the fall of Tarnovo the Ottoman forces turned on Nikopol. The tsar remained in the fortress for about two more years, but now as a mere Ottoman vassal — a "bey", as some documents call him.
His end is bound up with the war between Bayezid and the Wallachian voivode Mircea the Elder. After the battle of Rovine on 17 May 1395 the sultan crossed the Argeș and halted before Nikopol. A Turkish document from the Topkapı archive relates that "the land of Nikopol" then had a bey Shishman who, like the Wallachian voivode, paid tribute to the sultan; Bayezid asked him for boats to cross the river, and as soon as he was on the other bank he ordered him killed. Bulgarian chronology gives 29 October 1395 as the day of his execution. Schiltberger writes that the tsar died in prison and that his son Alexander embraced Islam to save his life.
4.The Battle of Nicopolis (1396)
In the summer of 1396 the crusading army of King Sigismund of Hungary came down the Danube — Hungarians, French knights, Germans. Vidin opened its gates; at Rahovo the crusaders forced their way in past the Turkish garrison and massacred the inhabitants. In September they reached Nikopol, where the Ottomans were even more strongly entrenched, and laid siege to the fortress — for about fifteen days, according to Boucicaut.
Meanwhile the main Ottoman army, led by Bayezid in person, arrived and occupied the heights five or six kilometres south of the town. Schiltberger, who took part in the campaign, speaks of 200,000 men, and says the reconnaissance was carried out by Mircea the Elder's men — the figure is clearly exaggerated. Between Sigismund and his allies a quarrel over tactics broke out once again.
On the morning of 25 September 1396 the French knights charged up the hillside at the small troop of light Turkish cavalry in view, not knowing that the sultan's main forces were hidden behind the ridge. The attack ended in catastrophe for the whole crusading army. Bayezid ordered all the Christian prisoners to be killed except those worth a ransom; among them was Marshal Boucicaut, while the sixteen-year-old squire Schiltberger survived to describe the "three Bulgarias" later on. Sigismund escaped on a Venetian ship down the Danube and stayed for a time in the capital of the Dobruja despot Ivanko before going on to Constantinople. The rout at Nicopolis also sealed the fate of Vidin.