As the town became more prominent, it was repeatedly attacked by the Hanseatic League, and in 1368 successfully invaded during the Second Danish-Hanseatic War. As the fishing industry thrived in Copenhagen, particularly in the trade of herring, the city began expanding to the north of Slotsholmen. In 1254, it received a charter as a city under Bishop Jakob Erlandsen who garnered support from the local fishing merchants against the king by granting them special privileges. In the mid 1330s, the first land assessment of the city was published.