The city's oldest Roman era ruins were uncovered in the 1960s. Later, during the Middle Ages, it became one of the most important strongholds of the Hungarian Kingdom. The fortress had a significant role in the southern shield line of Hungary, keeping the whole of Western Europe safe from the attacks of the Ottoman Empire. Instead of conquerors, today Nagykanizsa attracts thousands of dental tourists as the modern age's invaders. The name Kanizsa is of Slavic origin (Knysa), and means "belonging to a prince". It refers to the fact that the region was the property of an aristocrat.
The name Kanizsa was first mentioned in a document in 1245. The Kanizsai family continued building the castle and constructed a rectangular castle with an enclosed back yard on an islet in the River Kanizsa. The town and the castle were in their prime in the first half of the 16th century, when Kanizsa became a centre of trade with Italy and Styria.
Szigetvár and Kanizsa became the most important strongholds in southern Hungary. In 1600 the Turkish army occupied the castle. This castle was the center of an Ottoman eyalet including the sanjaks of Sigetvar, Kopan, Valpuva, Siklos, Nadaj and Balatin until 1690 (see Ottoman Hungary), when the city was invaded by the Habsburg armies.
In 1601, during the Ottoman-Habsburg War of 1593-1606, a siege began on September 9 and ended on November 18. The Habsburg forces were commanded by Ferdinand the Archduke of Austria, and Tiryaki Hasan Pasha was defending the castle. Hasan Pasha won the fight against the ten times bigger army of crusaders with many cunning military ploys, and was raised to the rank of Vizier.
At the beginning of the 18th century, the holder of the castle moved German, Croatian and Serbian settlers into the deserted town. A particularly mixed ethnic group lived in a suburb called Kiskanizsa. After the Turks were driven out the town lost its strategic significance, so the Vienna war council demolished the
