The loss of Christian forts at Temesvár and Szolnok in 1552 were blamed on mercenary soldiers within the Hungarian ranks. When the Ottoman Turks turned their attention to the northern Hungarian town of Eger in the same year, few expected the defenders to put up much resistance, particularly as the two great armies of the Ottoman lords Ahmed and Ali, which had crushed all opposition previously, united before Eger.

Eger was an important stronghold and key to the defense of the remainder of Hungarian soil. North of Eger lay the poorly reinforced city of Kassa (present-day Košice), the center of an important region of mines and associated mints, which provided the Hungarian kingdom with large amounts of quality silver and gold coinage. Besides allowing a takeover of that revenue source, the fall of Eger would also enable the Ottoman Empire to secure an alternate logistic and troop route for further westward military expansion, possibly allowing the Turks to lay sieges to Vienna more frequently.

Kara Ahmed Pasha laid siege to the Castle of Eger, located in the northern part of the Kingdom of Hungary, but the defenders led by István Dobó repelled the attacks and defended the castle. The siege has become an emblem of national defense and patriotic heroism in Hungary.