Complex sentence: After leaving the RAF he travelled around europe with his wife, Sarah; this left him with an interest in the Cold War, a fact demonstrated in 2005 when his first major book, "Four Minute Warning" was published by Tempus Publishing.
Split into simpler sentences: After leaving the RAF he travelled around Europe with his wife, Sarah; this left him with an interest in the Cold War. This interest was demonstrated in 2005 when his first major book, "Four Minute Warning" was published by Tempus Publishing.