In January 1566 Sultan Suleiman I had ruled the Ottoman Empire for 46 years and went to war for the last time.
He was 72 years old and, although having gout to the extent that he was carried on a litter, he nominally commanded his thirteenth military campaign.
On 1 May 1566 the Sultan left Constantinople at the head of one of the largest armies he had ever commanded.

His opposite number, Count Nikola IV Zrinski, was one of the largest landholders in the Kingdom of Croatia, a seasoned veteran of border warfare, and a Ban (Croatian royal representative) from 1542 to 1556.
In his early life he distinguished himself in the Siege of Vienna and pursued a successful military career.

Suleiman's forces reached Belgrade on 27 June after a forty-nine-day march.
Here he met with John II Sigismund Zápolya who he earlier promised to make the ruler of all Hungary.
Learning of Zrinski's success in an attack upon a Turkish encampment at Siklós, Suleiman decided to postpone his attack on Eger (German: Erlau) and instead attack Zrinski's fortress at Szigetvár to eliminate him as a threat.
In January 1566 Sultan Suleiman I had ruled the Ottoman Empire for 46 years and went to war for the last time. He was 72 years old and, although having gout to the extent that he was carried on a litter, he nominally commanded his thirteenth military campaign. On 1 May 1566 the Sultan left Constantinople at the head of one of the largest armies he had ever commanded.
His opposite number, Count Nikola IV Zrinski, was one of the largest landholders in the Kingdom of Croatia, a seasoned veteran of border warfare, and a Ban (Croatian royal representative) from 1542 to 1556. In his early life he distinguished himself in the Siege of Vienna and pursued a successful military career.
Suleiman's forces reached Belgrade on 27 June after a forty-nine-day march. Here he met with John II Sigismund Zápolya who he earlier promised to make the ruler of all Hungary. Learning of Zrinski's success in an attack upon a Turkish encampment at Siklós, Suleiman decided to postpone his attack on Eger (German: Erlau) and instead attack Zrinski's fortress at Szigetvár to eliminate him as a threat.
Siege of Szigetvár