RMS Lusitania (named after the Roman province corresponding to modern Portugal and portions of western Spain) was a British ocean liner launched by the Cunard Line in 1906.

Lusitania, British ocean liner, the sinking of which by a German U-boat on May 7, 1915, contributed indirectly to the entry of the United States into World War I. The sinking led to the deaths of 1,198 people, including 128 U.S. citizens, which led to a wave of indignation in the United States.

The RMS Lusitania was a British-registered ocean liner that was torpedoed by an Imperial German Navy U-boat during the First World War on 7 May 1915, about 11 nautical miles (20 kilometres) off the Old Head of Kinsale, Ireland.

The RMS Lusitania was a British ocean liner torpedoed and sunk by the German submarine U-20 on 7 May 1915, becoming a casualty of World War I. 128 American civilians died in the attack, turning American opinion against Germany, making the sinking a turning point of the war.

The Lusitania sank in 18 minutes in 300 feet, or 91 meters, of water. A graph shows that, of the 1,959 passengers on board the ocean liner, 1,198 drowned. Of those who drowned, 128 were U.S. citizens. When it sank, the ship was carrying 173 tons of artillery shells and rifle ammunition.