Colditz Castle is located on a hill spur over the river Zwickauer Mulde, a tributary of the River Elbe. In 1046, Henry III of the Holy Roman Empire gave the burghers of Colditz permission to build the first documented settlement at the site. During 1158, Emperor Frederick Barbarossa made Thimo I the Lord of Colditz, and major building works began. By 1200, the town around the market was established. During the Middle Ages, the castle was used as a lookout post for the German Emperors and was the hub of the Reich territories of the Pleissenland.
As a result of family dynastic politics, the town of Colditz was incorporated into the Margraviate of Meissen. During 1430, the Hussites attacked Colditz and set town and castle on fire. Around 1464, renovation and new building work on the castle were done by order of Prince Ernest, who died in Castle Colditz in 1486. During the reigns of Electors Frederick III the Wise and John the Gentle, Colditz was a royal residence of the electors of Saxony.
During 1504, the servant Clemens the baker accidentally set Colditz afire, and the town hall, church, castle and a large part of the town was burned. During 1506, reconstruction began and new buildings were erected around the rear castle courtyard. During 1523, the castle park was converted into one of the largest zoos in Europe. During 1524, rebuilding of the upper floors of the castle began. There is nothing more to be seen of the original castle, where the present rear of the castle is located.
The structure of the castle was changed during the long reign of the Elector Augustus of Saxony (1553–86), and the complex was reconstructed into a Renaissance style castle from 1577 to 1591, including the portions that were still in the Gothic architectural style.
In 1694, its then-current owner, King Augustus the Strong of Poland, began to expand it, resulting in a second courtyard and a total of 700 rooms.
During the 19th century, the church space was rebuilt in the neo-classic architectural style, but its condition was allowed to deteriorate. The castle was used by Frederick Augustus III, Elector of Saxony as a workhouse to feed the poor, the ill, and persons who had been arrested. It served this purpose from 1803 to 1829, when its workhouse function was assumed by an institution in Zwickau. During 1829, the castle became a mental hospital for the 'incurably insane' from Waldheim. During 1864, a new hospital building was erected in the Gothic Revival style, on the ground where the stables and working quarters had been previously located. It remained a mental institution until 1924.
When the Nazis gained power during 1933, they converted the castle into a political prison for communists, homosexuals, Jews and other people they considered undesirable. Starting 1939, allied prisoners were housed there. After the outbreak of World War II, the castle was converted into a high security prisoner-of-war camp for officers who had become security or escape risks or who were regarded as particularly dangerous. Since the castle is situated on a rocky outcrop above the River Mulde, the Germans believed it to be an ideal site for a high security prison.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.