When did the man who Lord Frederick Charles Cavendish was a protege of last serve as Prime Minister?
William Ewart Gladstone:  In a career lasting over 60 years, he served as Prime Minister four separate times (1868–74, 1880–85, February–July 1886 and 1892–94), more than any other person, and served as Chancellor of the Exchequer four times.
i don't know