Task: Question Answering
Input (English): Passage: Amundsen was born in Fredrikstad (around 80 km from Christiania (now Oslo)), Norway, in 1872, the son of a ship-owner. In 1893, he abandoned his medical studies at Christiania University and signed up as a seaman aboard the sealer Magdalena for a voyage to the Arctic. After several further voyages he qualified as a second mate; when not at sea, he developed his skills as a cross-country skier in the harsh environment of Norway's Hardangervidda plateau. In 1896, inspired by the polar exploits of his countryman Fridtjof Nansen, Amundsen joined the Belgian Antarctic Expedition as mate, aboard Belgica under Adrien de Gerlache. Early in 1898 the ship became trapped by pack ice in the Bellinghausen Sea, and was held fast for almost a year. The expedition thus became, involuntarily, the first to spend a complete winter in Antarctic waters, a period marked by depression, near-starvation, insanity, and scurvy among the crew. Amundsen remained dispassionate, recording everything and using the experience as an education in all aspects of polar exploration techniques, particularly aids, clothing and diet.Belgica's voyage marked the beginning of what became known as the Heroic Age of Antarctic Exploration, and was rapidly followed by expeditions from the United Kingdom, Sweden, Germany and France. However, on his return to Norway in 1899, Amundsen turned his attention northwards. Confident in his abilities to lead an expedition, he planned a traversal of the Northwest Passage, the then-uncharted sea route from the Atlantic to the Pacific through the labyrinth of north Canadian islands. Having earned his master's ticket, Amundsen acquired a small sloop, Gjøa, which he adapted for Arctic travel. He secured the patronage of King Oscar of Sweden and Norway, the support of Nansen, and sufficient financial backing to set out in June 1903 with a crew of six. The voyage lasted until 1906 and was wholly successful; the Northwest Passage, which defeated mariners for centuries, was finally conquered. At the age of 34 Amundsen became a national hero, in the first rank of polar explorers.In November 1906 the American Robert Peary returned from his latest unsuccessful quest for the North Pole, claiming a new Farthest North of 87° 6′—a record disputed by later historians. He immediately began raising funds for a further attempt. In July 1907 Dr Frederick Cook, a former shipmate of Amundsen's from Belgica, set off northwards on what was ostensibly a hunting trip but was rumoured to be an attempt on the North Pole. A month later Ernest Shackleton's Nimrod Expedition sailed for Antarctica, while Robert Falcon Scott was preparing a further expedition should Shackleton fail. Amundsen saw no reason to concede priority in the south to the British, and spoke publicly about the prospects of leading an Antarctic expedition—although his preferred goal remained the North Pole. 
Question: What was the name of the expedition that became involuntary?
Output (English): Belgian Antarctic Expedition.