"Shannon" was ordered as part of the 1904–05 naval construction programme as one of the three "Minotaur"-class armoured cruisers. She was laid down on 2 January 1905 at Chatham Dockyard. The ship was christened on 27 April 1907 by Lady Carrington and commissioned on 19 March 1908 at the cost of £1,415,135. While fitting out in Portsmouth, "Shannon" was accidentally struck on 5 December 1907 by the battleship which had broken loose from her anchorage; both ships were only lightly damaged.