Complex sentence: Martineau served as parliamentary secretary to Prime Minister John Diefenbaker from 1959 to 1961 and then was Deputy Speaker of the House until 1962 when he joined the Canadian Cabinet as Minister of Mines and Technical Surveys.
Split into simpler sentences: Martineau served as parliamentary secretary to Prime Minister John Diefenbaker from 1959 to 1961. He and then was Deputy Speaker of the House until 1962, when he joined the Canadian Cabinet as Minister of Mines and Technical Surveys.