Complex sentence: Wilson was born in Dover to an Irish mother and an English father, who had a 40-year career in the British army from 15-year old boy bugler to Colonel in the RAMC (Royal Army Medical Corps) when he died in 1919.
Split into simpler sentences: Wilson was born in Dover to an Irish mother and an English father. His father had had a 40-year career in the British Army from 15-year old boy bugler to Colonel in the Royal Army Medical Corps when he died in 1919.