The location of Przemyśl castle and the earlier settlement lay on an important river crossing on a trade route running from the Black Sea to the Baltic Sea and through the Carpathian passes, and was a site of a fortified grod belonging to the Lendians (Lendizi), who were a West Slavic tribe descended from the White Croats.
In 1018, the Polish king Bolesław I Chrobry recaptured Przemyśl and built a stone Romanesque rotunda and palatium complex. Later, Casimir III the Great was responsible for the building of a Gothic castle in 1340, of which only a gate in Ogive style survives to this day. The buildings were damaged by the invading Vlachs in 1498, and rebuilt once again for Piotr Kmita Sobieński.
Przemyśl town elder Marcin Krasicki began the reconstruction of the castle in the Renaissance style in 1616. The works were supervised by the Italian architect Galleazzo Appiani. Towers were raised and attics finished, and more housing was attached, however after Krasicki's death, the reconstruction of the castle stopped.
From 1759 to 1762, Przemyśl mayor and future Polish king Stanislaw Poniatowski rebuilt the castle, rebuilding the ruins of two towers, the wall between them, building a new castle and adding stepped buttresses.
After the partition of the Commonwealth, the Austrians stationed troops in the castle. Eventually in 1865, the castle was handed over the city where from 1884 the dramatic society Fredreum has been based. During World War I, the Austrians held two thousand Russian prisoners in the castle. More restoration of the castle was carried out in 1920, and in 1980 two corner towers and curtain wall between them were rebuilt.References:
Kristiansten Fortress was built to protect the city against attack from the east. Construction was finished in 1685. General Johan Caspar von Cicignon, who was chief inspector of kuks fortifications, was responsible for the new town plan of Trondheim after the great fire of 18 April 1681. He also made the plans for the construction of Kristiansten Fortress.
The fortress was built during the period from 1682 to 1684 and strengthened to a complete defence fortification in 1691 by building an advanced post Kristiandsands bastion in the east and in 1695 with the now vanished Møllenberg skanse by the river Nidelven. These fortifications were encircled by a continuous palisade and thereby connected to the fortified city. In 1750 the fortress was modernized with new bastions and casemates to protect against mortar artillery.