Complex sentence: Colonel Humphrey Mews (1941-1990) was Deputy Private Secretary to His Royal Highness the Prince of Wales 1986-1988, and joined the Royal Artillery after Sandhurst.
Split into simpler sentences: Colonel Humphrey Mews was Deputy Private Secretary to His Royal Highness the Prince of Wales 1986-1988. He was born in 1941, and joined the Royal Artillery after Sandhurst.