Mein played association football at Wellington College and for the Royal Military Academy before joining the Royal Engineers in 1873, where he was described as a "brilliant" inside-left, who "worked untiringly", "making many good runs". Mein also played rugby for Richmond Rugby Club in 1874. At this time, the Royal Engineers were among the top football teams in England, having reached the final of the first FA Cup tournament in 1872 and again two years later, finishing on both occasions as runners-up. In the run to the 1875 final, Mein scored in a 3–2 victory over Clapham Rovers on 30 January 1875, helping to set up a semi-final against Oxford University. This was hard-fought, with the Engineers emerging victorious with a 1–1 draw followed by a 1–0 victory in the replay, thus reaching the FA Cup Final for the third time in four years. In the final, played on 13 March 1875 at Kennington Oval, the Engineers met the Old Etonians. The match was played in a strong gale and the Engineers spent most of the match against the gale, with the rules requiring ends to be changed after each goal. Alexander Bonsor scored for the Old Boys after 30 minutes followed by an equaliser from Capt Renny-Tailyour within five minutes. Shortly after the equaliser, Lt. Ruck collided with Cuthbert Ottaway who was forced to leave the field with a serious ankle injury; in his absence, the Old Boys were regarded as fortunate to have held on for a 1–1 draw. The replay was three days later; although the Engineers were able to field the same eleven as in the first match, the Etonians had to make four changes, losing the match 2–0, with both the Engineers' goals scored by Capt Renny-Tailyour. At the third attempt, the Royal Engineers won their first, and only, FA Cup Final.
Military career
Mein graduated from the Royal Military Academy after a year, when he was commissioned as a lieutenant in the Royal Engineers from 29 April 1873. Mein spent the first three years of his military service at Chatham before being sent to India in September 1876. In November 1878, Mein took part in the Anglo-Afghan War as assistant field engineer with the 2nd Division Peshawar Valley Field Force, and was involved in the opening battle of the war at Ali Masjid. Subsequently, Mein and the Royal Engineers were engaged in building forts along the lines of communication. Mein returned to Afghanistan, as assistant field engineer with the Khyber Line Force, for the second phase of the war in October 1879, taking part in the Wazir Khugianis Expedition, the Hissarak Expedition in April 1880 and the Lughman Valley Expedition in May 1880. For his services in the war, Mein was mentioned in dispatches and received the Afghanistan Medal. Mein remained in Bengal for most of the reminder of his military career, receiving promotion to captain on 8 January 1885 and to major on 1 October 1892, Mein returned to England in June 1893, and was posted to Portsmouth, before returning to India in February 1895. He was further promoted to lieutenant colonel from 24 January 1900 and to brevet colonel on 24 January 1904. Mein retired on an Indian pension of £700 per annum on 15 July 1911.
