 In 1873 , Vice Admiral Sir Geoffrey Hornby , commander of the Channel Fleet , transferred his flag to Agincourt as her sister Minotaur , his former flagship , was taken in hand for a refit that lasted until 1875 . That year Agincourt was paid off in turn for a refit and re @-@ armament that lasted until 1877 . During the Russo @-@ Turkish War of 1877 – 78 , the government became concerned that the Russians might advance on the Ottoman capital of Constantinople and ordered Hornby to form a Particular Service Squadron to show the flag at Constantinople and deter any Russian threat . Agincourt served as the flagship for his second @-@ in @-@ command and the squadron sailed up the Dardanelles in a blinding snowstorm in February 1878 . After those tensions faded , the ship returned to the Channel , where she served as second flag until 1889 including during Queen Victoria 's Golden Jubilee Fleet Review in 1887 . Over her active career , she served as flagship to no less than 15 admirals . That year she was again paid off and was subsequently held in reserve at Portsmouth until 1893 , when she was transferred to Portland for use as a training ship . 
