Cologne headquarters and workshops in Cologne. Other large companies based in Cologne include the REWE Group, TÜV Rheinland, Deutz AG and a number of Kölsch breweries. Cologne has the country's highest density of pubs per capita. The largest three Kölsch breweries are Reissdorf, Gaffel, and Früh. Historically, Cologne has always been an important trade city, with land, air, and sea connections. The city has five Rhine ports, the second largest inland port in Germany and one of the largest in Europe. Cologne-Bonn Airport is the second largest freight terminal in Germany. Today, the Cologne trade fair ("Koelnmesse") ranks as a major
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