CP Ships was a large Canadian shipping company established in the 19th century. From the late 1880s until after World War II, the company was Canada's largest operator of Atlantic and Pacific steamships. Many immigrants travelled on CP ships from Europe to Canada. In 1914 the sinking of the Canadian Pacific steamship RMS Empress of Ireland just before World War I became largest maritime disaster in Canadian history. The company provided Canadian Merchant Navy vessels in World Wars I and II. Twelve vessels were lost due to enemy action in World War II, including the RMS Empress of Britain, which was the largest ship ever sunk by a German U-boat.

RMS Empress of Ireland was a British-built ocean liner that sank near the mouth of the Saint Lawrence River in Canada following a collision in thick fog with the Norwegian collier Storstad in the early hours of 29 May 1914. Although the ship was equipped with watertight compartments and, in the aftermath of the Titanic disaster two years earlier, carried more than enough lifeboats for all aboard, she foundered in only 14 minutes. Of the 1,477 people on board, 1,012 died, making it the worst peacetime maritime disaster in Canadian history.