Complex sentence: He served at Supreme Headquarters Allied Powers Europe as a Staff Officer (Class 1) in the Joint Operation Centre from 1996 to 1997 and was Chief of Staff of 3rd (UK) Division prior to the Kosovo War.
Split into simpler sentences: He served at Supreme Headquarters Allied Powers Europe as a Staff Officer (Class 1) in the Joint Operation Centre from 1996 to 1997. He was Chief of Staff of 3rd (UK) Division prior to the Kosovo War.