The Army boasted one of the top club sides during the Victorian era, winning the world's oldest football competition.
The 2019 FA Cup final kicks off next month - a competition that includes a military team among its winners.
While the sides competing in this year's final are worth millions of pounds, in the mid-19th-century football was still finding its identity, with the military well-represented among the top players of the time.
Army side Royal Engineers AFC, founded in 1863, were one of the era's most successful, combining football with their regular military duties, and quickly became one of the sport's first 'big' teams.
'A Dominant Team'
Famous for developing an attractive passing game, the Royal Engineers quickly became regular contenders in what was then England's major competition.
Long before an era where European and international football would become the norm, the Sappers helped put football on the map when the sport was still making its way around the UK and primarily played by former public school pupils on an amateur basis.
Arguably, their best spell came during the 1870s - a decade before the Football League was founded in 1888, and when both football and the FA Cup were seeing a surge in popularity.
It was in the middle of the decade, 1875, when they became the only military team to have won the world's oldest football competition, and historians today look back on that Engineers side with high regard.
The club was formed and based at Chatham, Kent in the same year as the Football Association, under Crimean War veteran Major Francis Marindin's captaincy.
The Sappers reached their first FA Cup (or 'Football Association Challenge Cup' as it was then known) final nine years later, suffering a 1-0 defeat at Kennington Oval to another successful side of the era, the Wanderers.
"They were part of the evolution of tactics - most teams then tended to play with seven or eight forwards, and dribble it towards goal," says Professor Porter.
"They'd mass behind the ball like a scrum.
"The Royal Engineers were one of the first teams to go on tour in 1873 when they were quite famous for their passing game.
"They went to places like Sheffield, Derby and Nottingham - this is when their tactics began to spread North."
"The FA Cup was the making of football, and it captured the imagination. It put the game on the map.
"The Royal Engineers were the most successful English side from around 1871 until 1875, winning 84 out of 87 matches, according to some records - this is when they were at their peak."
The Sappers also received recognition on the international stage, with eight of their players receiving international caps while playing for the club.
Six played for England, and two for Scotland; the twice England-capped British Army officer Lieutenant Colonel Pelham George von Donop the most experienced international footballer to wear Sappers colours.