What was the sister ship of the ocean liner RMS Queen Mary?

RMS Queen Elizabeth was an ocean liner operated by the Cunard Line. With her sister ship Queen Mary she provided luxury liner service between Southampton in the United Kingdom and New York City in the United States, via Cherbourg in France. She was also contracted for over 20 years to carry the Royal Mail thus enabling her to carry the prestigious Royal Mail Ship (RMS) designation, as the second half of the two ships' weekly express service.

While being constructed in the mid-1930s by John Brown and Company at Clydebank, Scotland, she was known as Hull 552 but when launched, on 27 September 1938, she was named in honour of Queen Elizabeth, who was then Queen Consort to King George VI and in 1952 became the Queen Mother. With a design that improved upon that of Queen Mary, Queen Elizabeth was a slightly larger ship, the largest passenger liner ever built at that time and for 56 years thereafter. She also has the distinction of being the largest-ever riveted ship by gross tonnage. She first entered service in February 1940 as a troopship in World War II, and it was not until October 1946 that she served in her intended role as an ocean liner.