How many journeys did Shackleton make to Antarctic?

Ernest Shackleton made three major journeys to Antarctica. His first was as second-in-command on the Discovery Expedition from 1901 to 1904. He later led the Nimrod Expedition in 1907-1909 and the famous Imperial Trans-Antarctic Expedition in 1914-1917, during which his ship, the Endurance, became trapped in ice.