Port city of southwestern Norway, originally called Bjørgvin, and founded in 1070 AD by King Olaf III. About 1100, a castle was built on the northern edge of the Vågen harbor, and Bergen became commercially and politically important; it was Norway's capital in the 12th and 13th centuries. Excavations in the Bryggen, the harbor area, have revealed a sequence of levels that illustrate the area's evolution from the 11th century onwards. The levels have been accurately dated by a series of fires which occurred at various stages of Bergen's history. Waterlogged conditions have preserved many of the timber buildings, streets, and quays. The 11th-century houses and warehouses were on piles and had sills at ground level, while jetties became popular in the Hanseatic period (14th and 15th centuries). The excavations revealed a remarkable collection of imported pottery from all over Europe as well as quantities of leather and wooden objects. Parts of three trading ships or freighters were also found, their timbers having been re-used in the buildings.