Helmer Julius Hanssen, was a Norwegian sailor, pilot and polar explorer, he participated in three of the polar expeditions led by Roald Engelbregt Gravning Amundsen, was a Norwegian explorer of polar regions, he was the leader of the Antarctic expedition of 1910–12, which was the first to reach the South Pole, on which date?
Roald Amundsen:  As the leader of the Antarctic expedition of 1910–12, which was the first to reach the South Pole, on 14 December 1911, he was a key expedition leader during the Heroic Age of Antarctic Exploration.
i don't know