HMS Britannia (1762)

HMS Britannia was a 100-gun first-rate ship of the line of the Royal Navy. She was ordered on 25 April 1751 from Portsmouth Dockyard to the draught specified in the 1745 Establishment. Her keel was laid down on 1 July 1751 and she was launched on 19 October 1762. The cost of building and fitting totalled £45,844/2s/8d. Her main gundeck armament of twenty-eight 42-pounder guns was later replaced by 32-pounders. In the 1790s ten of her quarterdeck guns and two of her forecastle guns were replaced by the same number of 32-pounder carronades.

Britannia was first commissioned in September 1778, and saw service during the War of American Independence. From 1793–1795 she was the flagship of Vice-Admiral Hotham. She fought at the Battle of Cape St Vincent and at the Battle of Trafalgar, where she carried the flag of Rear-Admiral of the White William Carnegie, Earl of Northesk. She lost 10 men killed and 42 wounded at Trafalgar, and following that battle she was laid up in ordinary in the Hamoaze at Plymouth in 1806.

The ship was renamed on 6 January 1810 as HMS Princess Royal, then on 18 January 1812 as HMS St George and once more on 2 June 1819 as HMS Barfleur.

She was third of seven ships to bear the name Britannia, and was broken up at Plymouth in February 1825.

She was known as 'Old Ironsides' long before USS Constitution.