During the spring, Ulama Beğ's army crossed the Drava and broke into Muraköz (Međimurje), raided, and attacked Kanizsa, owned by Tamás Nádasdy, but it was well defended by Nikola IV Zrinski, the Ban of Croatia, who sallied out and attacked Ulama Beğ’s camp, forcing the Ottomans to flee.

As soon as my highest command reaches you, ask in a friendly manner the gâvurs of the castle named Valpovo to surrender, grant mercy to the infidels with vile morals in it and see to it that everything is done according to their wishes.

If those wicked accept your highest mercy and offer the castle, immediately take possession of it, and until my arrival see to its custody and protection, as necessary.

"In early May, Murâd Beğ, following the Ottoman Sultan Suleyman's orders, rode to Valpovo and, under a flag of parley, asked for the castellan, and gave the garrison an opportunity to surrender on generous terms.

Know that I will not surrender the castle to you, do not tire your tongue with vain speech, nor strive after your unattainable desire, but go home and be at ease; then when the Pâdişâh arrives here, I will give it up to him.” Murâd Beğ angrily responds:  “Hey damned one!

[8] On May 10, Murâd Beğ’s army arrives at Valpovo and begins to build entrenchments and firing positions for cannons brought from Osijek.

Murâd Beğ sends a report[9] to the Sultân claiming that his men defeated the Christians, killing many, taking some captive, and forcing many others into the river, where they drown.

[10] The Sultân sends Ahmed Paşa, Beğlerbeğ of Rumelia, the commander of the vanguard, to the Drava River to build a bridge, and then take Siklós and Pécs.

He also ordered Kasım Beğ, the sançakbeğ of Mohács, to travel north and clear the way from Szekszárd to Buda of any possible ambushes.

On June 13, after the siege cannons created breaches in Valpovo's walls, a large assault was made but repulsed by the defenders.

By June 22, 3,137 cannonballs hit the Valpovo walls, most of which were shattered, half the soldiers were dead, and almost all the rest were either wounded or sick.

Also on June 22, from his estate at Lukavec, Nikola IV Zrinski wrote to Tamás Nádasdy, a former Ban of Croatia, asking for help to rescue Valpovo.

Some Hungarian sources claim that though Árky and his men were promised safe passage from Valpovo, they were killed in an ambush by soldiers desiring booty.