Leading a Ottoman raiding army, Ali Bey Evrenosoğlu, the son of Evrenos, who had faced defeat in the 1432 invasion, marched forward with the voluntary assistance of Vlad II Dracul, the Wallachian voivode disloyal to Hungary.

[2] Upon hearing of the invasion, Desiderius Losonci, the Transylvanian voivode, ordered mobilization, but the nobility's reluctance to fulfill their defense duties forced him to prioritize evacuating people and livestock from the affected regions.

[2] After the enemy withdrawal, the voivode sought to punish lords and nobles who failed to take up arms, but Queen Elizabeth of Luxembourg's pardon upon her return from Bohemia spared them and restored their estates.

Following the diet of Buda, Albert promptly took action to protect the southern regions as the Turks had indeed carried out their threats from the previous year, pouring a massive army into Serbia, raising concerns of an invasion into Hungarian territory.

The Banat of Severin was deemed the most vulnerable part of the country due to its elongated shape, exposing it to enemy attacks from the east, under Ottoman control in Wallachia, as well as from the south and west.

However, compliance with the diet's resolution was slow and reluctant, mainly because the poorer nobles, oppressed by the magnates, sought to shift the burden of military service onto the king, arguing that the danger could be repelled by royal banners and hired mercenaries.

Sultan Murad II set out at the end of May with a formidable army, allegedly numbering 130,000 soldiers, primarily to occupy Serbia, devastating the Morava region.

[6] This was the situation when the king and queen arrived at the camp near Szeged at the end of July, where they learned that the troops called to arms were only slowly assembling, and within their ranks, there was a high degree of indiscipline and dissatisfaction.

Albert promised at this time that he would personally organize and lead the army to be raised, and the 31 nobles present at the council pledged to fully support the king in collecting the aforementioned tax.

[6] He did not consider it acceptable that, amidst such difficult and complex circumstances, with the three countries at odds with each other and the throne, they should fall under the capricious rule of a weak, biased, and easily influenced woman.

Upon arrival, he found the church already bustling with a large crowd, necessitating the removal of all but the clergy, nobles, and elder knights for the smooth execution of the coronation ceremony.

[8]: 236  As Cardinal Dionysius, Archbishop of Esztergom, commenced the high mass invoking the Holy Spirit, King Władysław shed his royal garments and received blessings and anointing.

He then adorned himself with various regal symbols, each carrying significant historical weight, notably the apostolic cross purportedly given to St. Stephen by the pope in honor of Hungary's embrace of Christianity.

Returning to the royal castle, Władysław hosted a lavish feast for dignitaries from both realms, concluding the day with joyful celebrations, dances, and games, marking the auspicious beginning of his reign as King of Hungary.

[8]: 236 As different factions within Hungary clashed with each other domestically, Sultan Murad took advantage of the discord by deploying a substantial force to besiege Belgrade, a critical fortress positioned at the junction of the lower Sava and Danube rivers, in early 1440.

Unable to break their resolve, the Turks resorted to digging a tunnel beneath the walls, a plan that was foiled by Talovac's counter-tunneling and a strategically timed explosion that decimated the enemy forces underground.

King Władysław entrusted him with the defense of the southern regions, appointing him as Ban of Severin, Count of Temes, and Voivode of Transylvania, while also assigning him the role of Captain of the Plains.

[12] When Isa Bey Ishaković, the commander of Szendrő Castle, entertained the idea of seizing Belgrade, despite the fortress's reputation for withstanding previous assaults, Hunyadi took action.

Despite an initial push from Isa Bey vanguard that drove back the Hungarian front lines, Hunyadi and Ilok's heavy cavalry stood firm, eventually launching a powerful counter-offensive.

Furious over the recent setback at Belgrade, Sultan Murad took decisive action in the spring of 1442 by dispatching Mezid Pasha, one of his seasoned commanders, with a formidable army comprising mainly European sipahis, estimated at around 80,000 soldiers by historians.

Upon receiving word of the Turkish advance, Nicholas of Ilok, rallied the Transylvanian nobility to arms and alerted John Hunyadi, stationed at Belgrade, of the imminent threat.

However, upon his arrival at Alba Iulia, the designated rendezvous point, Ottoman raiding parties had already ravaged the upper Maros River valley, leaving Ilok with meager armed support.

Many, fatigued by relentless storms, failed to mobilize in time, while others, caught off guard by the sudden enemy incursion, couldn't reach the assembly point, falling prey to marauding Turkish bands en route or during their preparations at home.

In such dire circumstances, Hunyadi found himself perplexed in Alba Iulia when reports arrived of returning Turkish forces emerging from the Maros area in small contingents.

[15] György Lépes, the valiant bishop of Transylvania, urged Hunyadi, typically composed and calculated in his actions, to seize the moment and confront the Turks with their modest forces.

[16][17] Driven by their initial fervor rather than strategic deliberation, Hunyadi and Lépes hastily assembled their troops, motivated more by the pursuit of glory than the disparity in enemy numbers, and launched an audacious attack against the Ottoman forces.

[17][18] However, the inhabitants of Sibiu and the fortress garrison, fully aware of the grim fate awaiting them if the enemy prevailed, mounted a fierce defense, thwarting the Turks at every turn.

[19][17][18] Mezid Pasha's defeat in Sibiu and the complete surrender of the Wallachian and Moldavian rulers greatly angered and provoked Sultan Murad, who decided to launch a comprehensive punitive campaign against Hungary the following year, intending to lead it personally.

[20] Learning that the Ottoman army had diverted towards Orșova, Hunyadi advanced parallel to them along the northern edge of the Transylvanian border mountains, aiming to block their invasion into Transylvania or Hungary, even if it meant a battle of life and death.

Then, Hunyadi descended from the mountains to block their path, surprising Sehabeddin, who fortified his position east of Orșova and west of Bistra, indicating mutual respect between the commanders.