Question: When did the man who Lord Frederick Charles Cavendish was a protege of last serve as Prime Minister?
Sentence (from "Lord Frederick Cavendish"): Lord Frederick Charles Cavendish {'1': ", '2': ", '3': ", '4': "} (30 November 1836 – 6 May 1882) was an English Liberal politician and "protégé" of the Prime Minister, William Ewart Gladstone.
Relevant evidence: Yes