In 1906, Brazil, striving to become the country with the strongest navy on the continent, ordered three ironclads from Great Britain. The development of one of them was delayed, mainly due to disputes about weapons. As a result, it was decided to arm the ship with fourteen 305 mm guns in seven turrets, which made her the record holder for the total number of her main battery barrels. Rio de Janeiro was laid down in 1911, but the Brazilian government was forced to sell the ship due to the economic situation. The battleship was acquired by the Ottoman Empire, which planned to put her into operation under the name "Sultan Osman." However, due to the outbreak of World War I, the ship was "leased" by the British government and joined the Royal Navy as HMS Agincourt.