After the Romans left Günzburg in the fifth century, the Alamanni tribe settled there. In around 700 the nearby castle of Ricinis was mentioned by the Cartographer of Ravenna as one of the five most important castles of Alemannia. In 1065 first documentary evidence appears of the town itself as Gunceburch. In 1301 the town became part of the Habsburg house and was developed into the centre of the Margraviate of Burgau; for a time (1803–1805) it was even the capital of all Further Austria.
After the construction of a castle and church in the south-western corner of the upper town (1577/80), Günzburg became the residence of Archduke Ferdinand II`s son Karl from 1609 until 1618. Margrave Karl was able to bring craft and trade to new heights, but later all his efforts were ruined by the Thirty Year War (1618–1648) in the course of which the number of Günzburg`s citizens went down from about 2,400 to some 800. The castle went up in flames (1703) and the citizens suffered badly under the occupation.
Today the the margraves' castle is the main tourist attraction. It is the only Habsburg castle built in Germany.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.