Of all the great liners that plied the North Atlantic, the first-named Mauritania was perhaps the most famous. Conceived with her sister Lusitania, the two ships were built as a British response to the increasing threat to Cunard's domination of the transatlantic passenger trade posed by the White Star Line which, in 1901, had passed into American ownership. Mauritania, at 31,938 tons, was launched on 20 September 1906, and was ready for trials exactly a year later. Her builders, Swan Hunter, handed her over to Cunard on 7 November 1907, and she sailed from Liverpool on her maiden voyage to New York on 16 November. On the return passage, she established a new record for the eastward crossing with an average speed of 23.69 knots, amply justifying the faith that had been placed in her giant turbine engines. In May 1908 she broke the record for the westbound crossing, only losing it to her sister a few months later. In September 1909 her average speed on the westward passage reached 26.06 knots and this new record was to stand for twenty years until broken by the German liner Bremen.
Both Lusitania and Mauritania were financed with Government loans and, when completed, Cunard received an annual subsidy for them in return for the promise to make the ships available to the Government in the event of a national emergency. When the Great War broke out, however, the authorities perceived at once that the two liners were far too large to be fitted-out as cruisers. At first Mauritania was laid up and then served as both a troop transport and a hospital ship. Lusitania continued the New York passenger service but fell victim to the German submarine U20 which torpedoed and sank her, with a huge loss of life, on 7 May 1915. After the Armistice in 1918, Mauritania was initially kept busy repatriating American troops until the following May, but on 27 June 1919, she cleared Southampton for New York and resumed the scheduled service with a new consort Aquitania.
In July, 1921, Mauritania was severely damaged by fire in Southampton and during the subsequent repairs, her accommodation was remodelled and her coal furnaces were converted to oil. Returning to service in March, 1922, she once again justified the capital spent on her conversion by setting new speed records and regularly averaging 25.5 knots. Despite her advancing age, she was becoming an institution among the travelling public and become almost a living legend as the 1920's drew to a close. When she lost the 'Blue Riband' to the Bremen in July 1929, she took up the challenge to recover it immediately with her fastest-ever crossings over the measured distance. Her average speed on the homeward run of 27.2 knots just failed to catch the Bremen's 27.9 but it was an astonishing achievement for the twenty-two year old veteran against the brand new German contender. The international economic climate sent her cruising to warmer waters after 1930, although she still did the occasional transatlantic crossing. She left New York for the last time on 26 September 1934, ironically the very same day that the Queen Mary was launched on Clydeside; Mauritania's reign was drawing to an end. In April 1935 she was sold for scrapping and, following the auction of her interior fittings, she sailed for Rosyth and the breaker's yard. The puplic mourned her as affectionately as they had honoured her in her prime. She had won for herself a place in maritime history such as no other steamship had ever done and it was not in the least surprising that even long after she had been broken up, she was still always known as 'The Grand Old Lady of the Atlantic'.