The Finnish–Novgorodian wars were a series of conflicts between Finnic tribes in eastern Fennoscandia and the Republic of Novgorod from the 11th or 12th century to the early 13th century. The wars' effect on the Finns' society contributed to the eventual Swedish conquest of western Finland in around 1249. The term used in Russian chronicles to refer to Novgorod's enemy, Yem, is unclear and probably referred to several different groups, even though etymologically it derives from the Finnish word Häme, which means Tavastia. Some of the groups identified as Yem may have been the inhabitants of Tavastland in south-central Finland, the West Finns in general, or a sub-group of Karelians on the northern coast of the Ladoga who descended from western Finns who had moved to the area earlier.