Complex sentence: He rose from private soldier in World War I to Air Marshal in 1948, and served as Chief of the Air Staff from 1942 to 1952, the longest continuous tenure of any RAAF chief.
Split into simpler sentences: He rose from being a private soldier in World War I to Air Marshal in 1948. He served as Chief of the Air Staff from 1942 to 1952, the longest continuous tenure of any RAAF chief.