Salisbury was again Secretary of State for India under Prime Minister Benjamin Disraeli . In 1878 , Salisbury became Foreign Secretary in the Disraeli government .
In 1874 when Disraeli formed an administration Salisbury returned as Secretary of State for India and in 1878 was appointed Foreign Secretary and played a leading part in the Congress of Berlin , despite doubts over Disraeli 's pro-Ottoman policy .