Early history
Settlements of the Neolithic and Bronze Age were found around Lake Zurich. Traces of pre-Roman Celtic, La T�ne settlements were discovered near the Lindenhof hill. In Roman times, Turicum was a tax-collecting point at the border of Gallia Belgica (from AD 90 Germania superior) and Raetia for goods trafficked on the Limmat river. After Emperor Constantine�s reforms in AD 318, the border between Gaul and Italy (two of the four praetorian prefectures of the Roman Empire) was located east of Turicum, crossing the River Linth between Lake Walen and Lake Zurich, where a castle and garrison looked over Turicum�s safety. The earliest written record of the town dates from the 2nd century, with a tombstone referring to it, discovered at the Lindenhof.
In the 5th century, the Germanic Alamanni tribe settled in the Swiss plateau. The Roman castle remained standing until the 7th century. A Carolingian castle, built on the site of the Roman castle by the grandson of Charlemagne, Louis the German, is mentioned in 835 (in castro Turicino iuxta fluvium Lindemaci). Louis also founded the Fraum�nster abbey in 853 for his daughter Hildegard. He endowed the Benedictine convent with the lands of Zurich, Uri, and the Albis forest, and granted the convent immunity, placing it under his direct authority. In 1045, KingHenry III granted the convent the right to hold markets, collect tolls, and mint coins, and thus effectively made the abbess the ruler of the city.
Zurich became an Imperial immediacy (Reichsunmittelbar or Imperial free city) in 1218 with the extinction of the main line of the Z�hringer family and attained a status comparable to statehood. During the 1230s, a city wall was built, enclosing 38 hectares, when the earliest stone houses on the Rennweg were built as well. The Carolingian castle was used as a quarry, as it had started to fall into ruin.
Emperor Frederick II promoted the abbess of the Fraum�nster to the rank of a
