The fortress of Oradea, the only late Medieval five-bastion fortress in Europe, is located in present-day Romania. The name of the town originates from the Hungarian word ‘vár’ meaning castle.
Between the 11th–12th centuries, the fortress was a fortification, made from earthen walls and a stockade, some stone walls and several wooden watch towers at the gates and the corners of the inner fortess. This fortress, however, was demolished during the Mongol invasion of 1241-42 – together with the town. A new medieval fortress, in an irregular hexagonal shape was erected in the 14th century, with towers, walls and strong gates.
The changes in warfare and politics in Central Europe in the 16th century made it necessary to construct a fortification, adapted to contemporary military requirements. The princes of Transylvania employed Italian engineers experienced in military architecture to design the new fortress. They designed a late Renaissance style pentagonal complex surrounded by ramparts. The fortress featured bastions of the neo-Italian type, which made defense more effective due to their triangular shape.
The fortress was constructed in two phases: first, the external defense ring was built, then the inner pentagonal castle. In the 16th century, John Sigismund Zápolya, the first prince of Transylvania, started the renovation of the fortess using state-of-the-art engineering. One of the bastions of the star-shaped fortress, the Királyfia bastion, was completed during his reign.
Construction was continued by Prince István Báthory, who invited Ottavio Baldigara, the renowned Italian military architect. Baldigara completed the construction of several bastions, including a palisaded earth bastion, which was later fortified in 1618 by Prince Gábor Bethlen, who invited Giacomo Resti, an influential northern-Italian architect to build a renaissance palace in the inner castle.
The main element of the concentric defense system was the moat surrounding the fortress, using the water of a nearby brook. When the Ottomans invaded Transylvania in order to punish Prince György Rákóczi II for his invasion of Poland, their 46-day siege of the fortress was only successful when the Ottomans managed to drain the moat. They took the fortress in 1660.
Further modifications and improvements were made on the Oradea Fortress in the 17th and 18th centuries, during the Hapsburg reign. Later, it lost its defensive role and today, sadly, it is listed by the World Monuments Fund among the 100 most endangered sites.