Either Lütold V von Regensberg or his son Ulrich established the fortified town of (Neu)-Regensberg around 1250. Ulrich died around 1280, and his son Lütold VIII had to sell Regensberg to Habsburg-Austria in 1302. The Habsburgs mortgaged the castle and town several times, and in 1407 the so-called Herrschaft Regensberg was acquired by the city of Zürich. From 1417 the castle became the seat of the bailiff of the bailiwick of Regensberg. On 6 June 1443 the council of Zürich forced their troops and the citizens to defend the fortified town, three days later the castle was conquered during the Old Zürich War by Zürich's contrahents, but not destroyed, and some months later manned again by Zürich troops.
On 9 September 1540 the town, but not the castle, was destroyed by fire, because it was separated from the Oberstadt by a ditch. The upper castle was rebuilt in the following year. From 1689 the castle and the upper town were fortified according to then modern standards. On 13 March 1798 the French revolutionary troops forced the council of the city republic of Zürich to abdicate, and the country bailiwicks were dissolved. After the end of the short-lived Helvetic Republic, Regensberg became the district capital, and the castle was the seat of the cantonal authorities, and in the main building there was the county jail until 1863.
Regensberg was designed as a fortified castle town and built by then modern contemporary criteria. The so-called upper castle (Oberburg) comprises a rectangular plaza as main square which is surrounded two rows of houses, and into the limestone a 57 m (187 ft) deep water well was carved. The lower castle (Unterburg) or lower town (Unterstadt) was probably built in the 14th century nestled at the castle's hill outside of the town wall. Therefore, it was not involved in the modernization of the upper castle in 1689.
Nowadays, the castle belongs to the Regensberg Castle Foundation. The round tower is still open to the public and offers a spectacular panoramic view of the surrounding region. In addition, information panels inside the tower relate the history of the small country town of Regensberg.References:
Narikala is an ancient fortress overlooking Tbilisi, the capital of Georgia, and the Kura River. The fortress consists of two walled sections on a steep hill between the sulphur baths and the botanical gardens of Tbilisi. On the lower court there is the recently restored St Nicholas church. Newly built in 1996–1997, it replaces the original 13th-century church that was destroyed in a fire. The new church is of 'prescribed cross' type, having doors on three sides. The internal part of the church is decorated with the frescos showing scenes both from the Bible and history of Georgia.
The fortress was established in the 4th century and it was a Persian citadel. It was considerably expanded by the Umayyads in the 7th century and later, by king David the Builder (1089–1125). Most of extant fortifications date from the 16th and 17th centuries. In 1827, parts of the fortress were damaged by an earthquake and demolished.