The first stone city walls were built in 1032. Around this time trade with Norway,
England and the northern Netherlands began to grow, thus increasing the importance of the city.
In fact, however, Bremen did not have complete independence from the Prince-Archbishops, in that there was no freedom of religion, and burghers were still forced to pay taxes to the Prince-Archbishops.
Bremen played a double role; it participated in the Diets of the neighbouring Prince-Archbishopric of Bremen as part of the Bremian Estates and paid its share of taxes, at least when it had previously consented to this levy. Since the city was the major taxpayer, its consent was generally sought. In this way the city wielded fiscal and political power within the Prince-Archbishopric, while not allowing the Prince-Archbishopric to rule in the city against its consent. In 1260 Bremen joined the Hanseatic League.In 1186 the Bremian Prince-Archbishop Hartwig of Uthlede and his bailiff in Bremen confirmed — without generally waiving the prince-archiepiscopal overlordship over the city — the Gelnhausen Privilege, by which Frederick I Barbarossa granted the city considerable privileges. The city was recognised as a political entity with its own laws.
Property within the municipal boundaries could not be subjected to feudal overlordship; this also applied to serfs who acquired property, if they managed to live in the city for a year and a day, after which they were to be regarded as