Complex sentence: The first Chairman of the Friends of the British Library was Christopher Henry Beaumont Pease, 2nd Baron Wardington; he would go on to become a Vice President in 1994, and finally President in 1999--a post he would hold until his death in 2005.
Split into simpler sentences: The first Chairman of the Friends of the British Library was Christopher Henry Beaumont Pease, 2nd Baron Wardington. He became a Vice President in 1994, and finally President in 1999--a post he would hold until his death in 2005.