Zemun Fortress

Zemun's medieval walls were built on top of the old Celtic, and then Roman town of Taurunum. The medieval walls are believed to be built by the Byzantine Empire. The first written mentions of the fortress are from the 9th century, and in the late 11th century it suffered great damage during the First Crusade. During the first half of 12th century, the town is repeatedly mentioned in relation to Byzantine–Hungarian clashes. John Kinnamos mentions that in 1127 the Hungarians captured the Belgrade Fortress, stripping its materials and using stone to build the Zemun fortress. A few decades later, Manuel I Komnenos took Zemun, and reversed the process. He took stones off the Zemun walls, transported them to the other side of the riverbank, and refortified Belgrade. The Ottomans additionally destroyed the town in 1397.

In 1411, Sigismund, the Holy Roman Emperor ceded Zemun to despot Stefan Lazarević. In 1441, it came under the possession of Đurađ Branković.

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