The Royal Wessex Rangers is a fictional British infantry regiment portrayed in the series. It is portrayed as a standard infantry battalion in the British Army during the late 1970s. During the three-year run of the show, the regiment is shown in different roles on different postings; to begin with, the battalion is on an operational tour of Northern Ireland at the height of The Troubles as light infantry, during which one of the sergeants of the battalion's 'B' Company, Colour Sergeant 'Jacko' Jackson (played by Michael Billington) is chosen to become a platoon commander, even though he is only an NCO. Subsequently, the battalion is posted first as a mechanised infantry battalion to West Germany as part of BAOR, then as a resident light infantry battalion to Hong Kong.