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 In January, the mean temperature is , while the mean temperature in July is . Temperatures can vary significantly over the course of a month with warmer and colder weather. Precipitation is spread evenly throughout the year with a light peak in summer due to showers and thunderstorms. Cologne is regularly affected by flooding from the Rhine and is considered the most flood-prone European city. A city agency ("Stadtentwässerungsbetriebe Köln", "Cologne Urban Drainage Operations") manages an extensive flood control system which includes both permanent and mobile flood walls, protection from rising waters for buildings close to the river banks, monitoring