[14] Transylvania had after the Battle of Mohács in 1526 recognized Ottoman suzerainty[15] and paid a tribute to the Porte and were given political and religious autonomy in return.

[citation needed] In the summer of 1663, an Ottoman army more than 100,000 strong under Grand Vizier Köprülü Fazıl Ahmed entered Habsburg Hungary and in September conquered the town of Érsekújvár (Nové Zámky).

[18] The invasion devastated eastern and southern Moravia, and the towns of Vsetín, Uherský Brod, Uherské Hradiště, Hodonín, Břeclav and Hustopeče were pillaged.

The Ottoman grand vizier aimed to force the Habsburg troops into battle and marched on Zrinski's stronghold Novi Zrin.

His army besieged and conquered the fortress after Montecuccoli refused a relief attack with inferior numbers and retreated to the Rába river.

[6][7] The major factor in the Habsburgs' decision for a peace treaty was the French threat to the much more valuable estates in the Netherlands, Germany and Italy.

[21] Moreover, the Imperial war effort lost some of its momentum after the victory of Saint Gotthard, as the French withdrew from the coalition while other German princes were reluctant to advance further east.

[citation needed] The Croats and Hungarians were outraged at the loss of the conquered territories and felt the initiative and momentum after the victory of Saint Gotthard should have been maintained.

[7] The peace held for 20 years until the Ottomans attacked Vienna for the second time in 1683 and were pushed back from Hungary in the following Great Turkish War (1683–1699).