Busy with the conquest of Eastern Anatolia, wars with Aq Qoyunlu and Mamluks, the Ottoman Empire reduced pressure on the Hungarian borders, and in 1503 concluded with the king Vladislav Danube Peace for 7 years.

At the same time, peace treaties did not stop the undeclared war: Ottoman raids, sieges of cities and retaliatory strikes of the Hungarians.

An attempt to organize a new crusade in 1514 against the Turks, who captured Knin, led to a powerful popular uprising, after which the authorities were afraid to resort to convening the people's militia even in the face of the Ottoman threat.

In 1521, Sderevo Pasha opened military operations against the Hungarians, then Suleiman attacked the southern borders of Hungary with large forces.

The defenders of the Belgrade citadel, besieged by the Grand Vizier Piri Mehmed Pasha and the Sultan, repelled 20 attacks, but without receiving the promised help from Ferdinand Habsburg, Poles and Czechs, capitulated on 20 August.

[11][12] King Lajos II fought with the Turks at Tolna, voivode Istvan Báthory at Petrovaradina, and John Zápolya in Transylvania against the corps akinji under the command of Muhammad Mikhal-ogly.

Francis I, taken prisoner by the Spaniards in the Battle of Pavia, began secret relations with the Turks, and in the spring of 1526 received the Sultan's consent to an alliance against the Habsburgs.

Emperor Charles V was an enemy of the Ottomans, but, forced to fight on several fronts, he considered the first task to be the defeat of the French and their ousting from Italy, the second was the reflection of Turkish aggression in the Mediterranean, and only in third place was the defense of the Middle Danube, which he provided to his brother Ferdinand.

[14] At the same time the most important task for the Habsburgs was to obtain the crowns of Bohemia and Hungary, and this was taken care of by the emperor Maximilian I, who concluded the Vienna Treaty of Mutual Inheritance with King Vladislav in 1515.

The Austrian Archduke's help depended on the position of the German Reichstag, which allocated funds for the war, but a reform movement developed in Germany, in the early stages of which Luther and his supporters declared that the Turks were God's punishment and could not be resisted.

[14] The Polish king Sigismund I the Old was connected by wars with the Teutonic Order, and therefore was forced on 1 December 1525, to make peace with the Turks, and to help his nephew as well could not.

[14] The mercenaries serving in the Hungarian army began to be grouped on the southern border, and they planned to convene another assembly if they still could not raise an adequate number of soldiers.

The assembly postponed the response until 22 December and finally again promised a smaller contingent (4,000 people), which it will send to Sopron by 25 May, so that afterwards they could strengthen the guard of the Hungarian and Croatian castles with them.

[d] Louis II was finally ready to make a decision to pay taxes and let the Turks pass to Austria, but papal and imperial diplomacy prevented him and 1525 in favor of continuing the war, but only if the Austrians and the Poles get involved.

However, the Nuremberg meeting was subsequently postponed for a year, and all aid was refused on the pretext that neither the Czech Republic nor Hungary had fulfilled the imposed conditions.

[16] But Hungary still trusted that the Poles, who had been friendly with them for centuries, as well as the Czechs, Romanians, Russians, Venetians and Austrians, could be mobilized against the Ottoman Turks,[e] but this was hindered by Hungarian internal strife, like the attacks on Báthory, who was suspected of embezzling seven hundred thousand forints and counterfeiting money.

In 1525 the Turks carried out several private operations on the Danube: they invaded Croatia, were defeated in Srem by the warlike bishop Pal Tomori, and unsuccessfully besieged the Jajce fortress, which was defended by Christoph Frangepan.

[17] Lajos II tried to obtain military assistance from the assembly of the Hungarian nobility, but the Diet on 12 July 1525, decided that the nobles themselves would not go to war, but would put mercenaries in their place.

On 27 July, after a 10-day siege, Petrovaradin was taken, then the Turks built a bridge across Drava at Esek, burned this city and moved inland, not meeting resistance, since the nobility From April to June, she quarreled with the king at the Diet, and did not make any decision.

Janos Zapolyai hurried to the rescue with a significant army, and had already reached Szegedin, but Istvan Bathory and other enemies of the Transylvanian governor on 28 August convinced the king to give battle with the available troops.