Complex sentence: Smith served in New Guinea from May 1942 to February 1943 at Port Moresby then in the Buna, Gona area of the Japanese beachheads, commanding the 14 th Brigade.
Split into simpler sentences: Smith served in New Guinea from May 1942 to February 1943. He was first stationed at Port Moresby then in the Buna, Gona area of the Japanese beachheads, commanding the 14 th Brigade.