Complex sentence: Pierre Picault (born 27 February, 1899) was, at age 109, France's oldest man and the last surviving French veteran of World War I following the death of 108 year old Fernand Goux on 9 November 2008.
Split into simpler sentences: Pierre Picault (27 February, 1899--20 November 2008) was, at age 109, France's last surviving French veteran of World War I and eldest man. He became the last French World War I veteran following the death of 108 year old Fernand Goux on 9 November 2008.