 In September 1876, "Mesudiye" became the flagship of the Ottoman Black Sea Squadron, though she did not see action in the Russo-Turkish War that broke out in April 1877.After the Ottoman defeat, the fleet was laid up at the Golden Horn and left largely unattended for the following twenty years.During this period of inactivity, "Mesudiye" received a minor modernization at the Tersâne-i Âmire shipyard on the Golden Horn.