The Hanseatic League (German: die Hanse, Dutch: de Hanze, Estonian: hansa, Latvian: Hanza Polish: Hanza, Swedish: Hansan) was an alliance of trading guilds. These guilds established and maintained a trade monopoly over the Baltic Sea and most of Northern Europe. This monopoly lasted for a time in the later Middle Ages and the Early Modern period, between the 13th and 17th centuries.