Frank Szécsényi, the Voivode of Transylvania, participated in the Serbian campaigns, likely including Székelys in his army who were tasked with recruitment, reconnaissance, pass guarding, and possibly espionage in neighboring voivodeships.

Sultan Bayezid opted not to confront his enemies directly and instead focused his forces in 1393 on the Bulgarian states of Tarnovo and Vidin in the Balkans, which either surrendered or fell under Ottoman control, thereby opening the path northwards for the Turks.

On October 10, 1394, the Ottoman army attacked his small state, prompting Mircea to seek refuge in Hungarian territory, resulting in the Sultan replacing him with Vlad I.

Under István Kanizsai's command in 1394, the legions of the Székelys breached the newly established border zone and advanced to Suceava with the royal army.

[1] This was unsurprising given Miklós Kanizsai's diplomatic skills and pivotal role in the military victory, as he had already discussed plans for a joint crusade with Western rulers.

They pushed the Turks back to the Danube and captured Turnu Măgurele, opposite the ancient city and castle of Nicopolis, held by a strong Turkish garrison.King Sigismund of Hungary, according to the Chronica Hungarorum, was thrilled by the impressive army gathered around him in Buda, expressing confidence in their strength.

Various historical sources provide differing figures for the composition of the crusader forces, with contributions from Kingdom of France, Republic of Venice, and Hungarian envoys.

Acknowledging the lack of experience in his son and other young leaders, Burgundy sought the guidance of Enguerrand VII, Lord of Coucy, a seasoned warrior and statesman, designating him as "chief counselor" to Nevers.

[2]: 549 The crusade departed from Dijon on April 30, 1396, journeying through Bavaria to the upper Danube, where they utilized river transport to join Sigismund in Buda.

Crossing the Danube at the Iron Gate, the crusaders targeted Vidin and then Oryahovo, where French actions led to tensions with their Hungarian allies.

They opted for a blockade strategy, surrounding the town and cutting off its supply routes, anticipating that the siege would serve as a precursor to a larger campaign aimed at relieving Constantinople.

Enguerrand VII de Coucy, one of the few proactive commanders, led a reconnaissance mission and engaged a Turkish force in a successful ambush, briefly reinvigorating the crusaders' morale.

Accounts of the ensuing battle vary, with some describing a chaotic clash where the French initially overwhelmed the Turkish front line but faced heavy resistance from archers and obstacles like sharpened stakes.

Despite recommendations from Coucy and Vienne to regroup and await Hungarian support, the younger knights, believing they had vanquished the entire Turkish army, insisted on pursuing the retreating enemy.

Chronicler Jean Froissart lamented the defeat, comparing it to the disastrous Battle of Roncesvalles, which saw the demise of all twelve peers of France, stating that Christendom had not suffered such a blow since then.

[2]: 566  The few survivors who made it back faced a harsh reception, with Count Rupert of Bavaria among them, arriving in beggar's rags only to succumb to his trials shortly after.

Jacques de Helly, charged by Bayezid to convey news of the victory and ransom demands, arrived in Paris on Christmas, bearing grim tidings.

Efforts to negotiate the captives' release spanned months, with Venice playing a crucial role as a conduit for communication and ransom exchange.

[6]: 69  It solidified Turkish control over the Balkans and posed a greater threat to central Europe, setting the stage for further Ottoman expansion and the eventual fall of Constantinople.