RMS Lancastria was a British ocean liner requisitioned by the Government of the United Kingdom during the Second World War. She was sunk on 17 June 1940 during Operation Aerial. Having received an emergency order to evacuate British nationals and troops from France, the ship was loaded well in excess of its capacity of 1,300 passengers. Modern estimates suggest that between 4,000 and 7,000 people died during the sinking — the largest single-ship loss of life in British maritime history.