Hasištejn (Burg Hassenstein) is a ruined medieval castle situated near Kadaň, Klášterec nad Ohří and Chomutov. The castle, first mentioned in Maiestas Carolina, was probably founded by Friedrich of Schönburg to guard the way from Prague to Saxony. The castle was seized by Václav IV of Luxembourg in the early 15th century and given to Nicholas of Lobkowicz.
The most renowned inhabitant of the castle was Bohuslav Hasištejnský z Lobkovic, a poet and traveller who was born in Hassenstein and lived there permanently from 1503 to his death in 1510. He gathered a huge library (comprising more than 650 volumes) in the castle, resulting in many scholars and humanists visiting Hasištejn Castle to borrow his books. Martin Luther and Philipp Melanchthon were among his visitors.
After Bohuslav's death in 1510, Hasištejn Castle began to fall into disrepair, which was exacerbated when it caught fire in 1560. Although the castle is now a ruin, its tower and walls remain standing to this day. While the castle became state property during the Communist regime, it was returned to the Lobkowicz family after 1989.
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.