The Dominion of Patagonia, commonly known as Patagonia, is a dominion of the United Britannic Commonwealth. Encompassing the southernmost portions of South America, Patagonia claims the southernmost dominion of the United Commonwealth. Patagonia is defined by the Andes Mountains on the Pacific Coast, the steppes on the Atlantic Coast, the Black River to the north, and the Tierra del Fuego archipelago to the south.
Patagonia was initially claimed by the Spanish, but would come under British dominance during the early 19th Century. Much of the British settlements were on the Atlantic coast, the Falkland Islands, and on the Strait of Magellan. Beginning in the 1860s, several Welsh settlements would be established, helping to populate the northern frontiers. A gold rush during the later half of the 19th Century would bring people to settle further south. Patagonia was granted dominion status in 1910.