What was Titanic's older Olympic-class sister ship called?

Titanic's older Olympic-class sister ship was RMS Olympic. Olympic was the lead vessel of the trio built for the White Star Line, making her both Titanic's older sister and the ship that gave the class its name.

Olympic's keel was laid down in Belfast in December 1908, several months before Titanic's. She was launched on 20 October 1910 and began her maiden voyage from Southampton on 14 June 1911. Titanic's construction proceeded alongside Olympic's, and Olympic's early career helped shape changes made to her younger sister.

The two ships were remarkably similar, but not identical. Titanic had altered promenade areas and more elaborate passenger accommodation, including larger suites and a Café Parisien. Olympic was also slightly lighter by gross tonnage. After Titanic sank, Olympic received major safety modifications, including many more lifeboats and strengthened watertight arrangements.

Unlike Titanic, Olympic served for about 24 years. She worked as a troop transport during the First World War, returned to passenger service, and was nicknamed “Old Reliable” before being withdrawn and scrapped in the 1930s.