Middle Ages thumb|left|150px|Rore Tower Aarau was founded around AD 1240 by the counts of Kyburg. Aarau is first mentioned in 1248 as Arowe. Around 1250 it was mentioned as Arowa. However the first mention of a city sized settlement was in 1256. The town was ruled from the "Rore" tower, which has been incorporated into the modern city hall.
middle ages thumb|left|150px|rore tower aarau was founded around ad 1240 by the counts of kyburg aarau is first mentioned in 1248 as arowe around 1250 it was mentioned as arowa however the first mention of a city sized settlement was in 1256 the town was ruled from the "rore" tower which has been incorporated into the modern city hall