 Its first seat was at Shanwu (near present-day Youyu, Shanxi); its later seats moved southeast to the more defensible sites at Yinguan (within present-day Shuozhou, Shanxi) and Guangwu (near present-day Daixian, Shanxi).The name derives from Yanmen Pass in Shanxi's Dai County.Yanmen, meaning "Wild Goose Pass" or "Wildgoose Gate", takes its name from the wild geese that migrate through the area.