Mühlhausen () is a town in the north-west of Thuringia, Germany, north of Niederdorla, the country's geographical centre, north-west of Erfurt, east of Kassel and south-east of Göttingen. Mühlhausen was first mentioned in 967 and became one of the most important cities in central Germany in the late Middle Ages. In the mid-13th century, it became a Freie Reichsstadt, an independent and republican self-ruled member of the Holy Roman Empire, controlling an area of approximately and 19 regional villages. Due to its long-distance trade, Mühlhausen was prosperous and influential with a population of 10,000 around 1500. Because it was spared from later destruction, Mühlhausen today has a great variety of historical buildings with one of the largest medieval city centres remaining in Germany, covering a surface of more than 50 hectares within the inner city wall and approximately 200 hectares overall. There are eleven Gothic churches, several patricians’ houses and a nearly completely preserved fortification. Johann Sebastian Bach worked as the city's organist in 1707–08. The theologian Thomas Müntzer, a leading person in the German Peasants' War, gave sermons here and was executed outside the city walls. John A. Roebling, the constructor of the Brooklyn Bridge, and Friedrich August Stüler, an influential architect in mid-19th-century Prussia, were born in Mühlhausen. Mühlhausen is within the Thuringian Basin, a flat and fertile area, on the Unstrut river on the eastern edge of the Hainich hills. History Middle Ages According to legend, in the 5th century Attila stayed at "Burg Mulhus" as a guest of his Thuringii allies before moving on to the Battle of the Catalaunian Plains. Within the north-eastern parts of the city centre around St. George's Church, sizeable archaeological finds have been made, relating to a large settlement of the Thuringii/Francia period (from the 6th to the early 10th century), which can be seen as the origin of the later city. Mühlhausen itself was first mentioned in 967 was part of a territory given by Otto II to his wife Theophanu. It belonged to the ab initio, i.e. there was no territorial lord other than the German emperor and the area was not the emperor's own property, so that it did not go to his son after his death but reverted to his successor as emperor, even if he was from another family. The emperors had a in Mühlhausen, which they often visited from Otto III to Henry III during