Upon winning the British government contract to provide the first regular mail and passenger service across the North Atlantic Ocean, the newly formed Cunard Steamship Company began a fortnightly service between Liverpool and Halifax, Boston and Quebec.

The vessels employed under this contract were to be of such a design that they might be available as troopships, and for transporting stores in wartime.

Four steamers, of similar size, were built - the Britannia, Acadia, Caledonia and Columbia. Britannia, Cunard's first ship, was launched on 5th February, 1840. She made her maiden voyage from Liverpool to Halifax and Boston on 4th July 1840, Samuel Cunard's Birthday, which, being the celebration day of American Independence, was viewed by many as a coincidence indicative of future prosperity. The passage, considered rapid then, took 14 days and 8 hours.

During a voyage in February 1844, Britannia became trapped in the ice in Boston Harbour but the citizens of the town cut a 7 mile escape channel at their own expense and Britannia was able to escape the ice filled harbour. Later, in September 1847, Britannia was stranded at Cape Race. She was subsequently repaired at New York. November 1848 saw the Britannia's last voyage on this service.

In March 1849 Britannia sailed from Liverpool to Bremen and became the Barbarossa, part of the former German Navy. In 1852 she was transferred to the Prussian Navy under the same name. Her career ended in 1880 when she was sunk whilst acting as a target ship.