Complex sentence: Ki-Zerbo founded a political party, the Party for Democracy and Progress/Socialist Party, of which he was chairman until 2005, and represented in the Burkina Faso parliament until 2006.
Split into simpler sentences: Ki-Zerbo founded a political party called the Party for Democracy and Progress/Socialist Party. He was its chairman until 2005, and represented it in the Burkina Faso parliament until 2006.