 After the war , Marlborough was assigned to the Mediterranean Fleet , where she took part in the Allied intervention in the Russian Civil War in the Black Sea in 1919 – 20 . She was also involved in the Greco @-@ Turkish War . In 1930 , the London Naval Treaty mandated that the four Iron Duke @-@ class battleships be discarded ; Marlborough was used for a variety of weapons tests in 1931 – 32 , the results of which were incorporated into the reconstruction programme for the Queen Elizabeth @-@ class battleships . 
