Complex sentence: On 23 July 1987, he was elected Deputy Leader of the National Party, a position in which he remained until 23 March 1993 and was the only person to served as deputy to three Nationals leaders (Ian Sinclair, Charles Blunt and Tim Fischer).
Split into simpler sentences: On 23 July 1987, he was elected Deputy Leader of the National Party, a position in which he remained until 23 March 1993. He was the only person to serve as deputy to three Nationals leaders (Ian Sinclair, Charles Blunt and Tim Fischer).