Cologne City Hall and 1096 were followed by the formation of a "commune" and first municipal structures as a basis for urban autonomy. In order to consolidate their economic and political rights, Cologne burghers established fraternities and trade guilds (most notably the "Richerzeche"). In the 1106 war of succession between Emperor Henry V and his father Emperor Henry IV, they took deliberate opposition to the archbishop, after which they gained benefit in regards to the city's territorial expansion over the following years. As – at the time – one of Europe's busiests trading ports and largest city in Germany, the population of Cologne
Cologne City Hall immediacy as a free imperial city. In 1388 Pope Urban VI signed the charter for the University of Cologne, Europe's first university to have been established by citizenry. On 14. September 1396 the constitution of Cologne came into effect and the Cologne gaffs and guilds ("Gaffeln" and "Zünfte") assumed power in the council. Following the tradition of Roman consuls, the council was headed by two elected Burgomasters (Mayors) until the year 1797, when council and constitution were replaced by the Napoleonic and later code civil. Since 1815 the city council is led by one Oberbürgermeister (Lord Mayor). During the bombing