History of Cologne (Cologne Tower), one of Cologne's most prominent highrises. Secondly, a permanent improvement in traffic infrastructure, which makes Cologne one of the most easily accessible metropolitan areas in Central Europe. Due to the economic success of the Cologne Trade Fair, the city arranged a large extension to the fair site in 2005. The original buildings, which date back to the 1920s, are rented out to RTL, Germany's largest private broadcaster, as their new corporate headquarters. A controversy started after Muslims in Cologne sought to build a mosque. Most important for the history of Cologne since the Middle Ages is the Cologne
Cologne City Hall gradually changed from a mainly feudal society to free citizens. Documents from the years 1135 and 1152, recorded "a house in which citizen convene", referring to the first established council hall, at the location of today's town hall. The coat of arms of Cologne, first mentioned in 1114, is Europe's oldest municipal coat of arms. By 1180, the citizens of Cologne won a legal battle against Philip I, Archbishop of Cologne, for another extension of Cologne's city walls. With the Battle of Worringen fought in 1288, Cologne became independent from the Electorate and on 9. September 1475 officially gained Imperial