The 17th century saw Sweden grow into a major European power, reflected in the development of the city of Stockholm. From 1610 to 1680 the population multiplied sixfold. In 1634, Stockholm became the official capital of the Swedish empire. Trading rules were also created that gave Stockholm an essential monopoly over trade between foreign merchants and other Swedish and Scandinavian territories.  In 1697, Tre Kronor (castle) burned and was replaced by Stockholm Palace.