Complex sentence: Køge received its privileges from the king in 1288, but was a relatively unimportant town until the 1500s when it began to grow with the assistance of several monarchs, and was successful in having several seasonal markets moved there from other nearby towns.
Split into simpler sentences: Køge received its privileges from the king in 1288, but was a relatively unimportant town until the 1500s when it began to grow with the assistance of several monarchs. Køge succeeded in having several seasonal markets moved there from other nearby towns.