Coats Island, Nunavut, 5498 km2, is one of several islands that guard the northern entrance to Hudson Bay. Known originally as Cary Swan Nest, a name still applied to its SE point, it received its modern name from William Coats, a sea captain who made many voyages into the bay for the Hudson's Bay Company 1727-51. For the most part flat or gently rolling, it was believed by early mariners to be joined to the larger Southampton Island. During the 1860s, American whalers began to visit the bay and discovered the straits (Fisher and Evans) that separate the islands. Uninhabited today, it was probably occupied seasonally by the Sadlermiut Inuit of Southampton Island, who were annihilated by an epidemic after 1900.