In January 1916, Allen and his regiment were sent to France where they joined the 2nd C.M.R.'s to make up a battalion. Allen fought in the Ypres Salient at the Hooge and Sanctuary Wood, on the Somme, Vimy Ridge and at Passchendaele. On October 27th, 1917 he was wounded in the leg by a burst of shrapnel during the battle of Passchendaele, and evacuated back to England.

While he was convalescing from his injury he applied with the Royal Air Force. He was accepted into the Air Force in January 1918 and sent to Egypt to begin pilot training where he rose to the rank of Second lieutenant. After the war he travelled extensively throughout the Middle East before returning home to Canada in October 1919.

Allan's parents, Harry and Ellen Church had both moved to Alberta in the late 1880’s from Ontario and were married in Calgary in 1892. Harry worked as a carpenter in Calgary building homes and schools around the city. He also built a number of homes in Banff and helped build the Horse Barns in Victoria Park at the Stampede Grounds, and the Bus Barns for the Calgary Transit Streetcar Company.

Harry and Ellen had eight children, of whom the eldest was Allan Harrison Church, born in Calgary on June 30th, 1893. As a young lad Allan had loved horses and after acquiring some of his own he went into business for himself, getting paid to round up neighbours cows on horseback and taking them out to pasture in what is now South Calgary.

Allan also drove wagons delivering orders for Pat Burns' Pacific Meats, which had their stables across from the Palliser Hotel. He also remembers watching the first Calgary Stampede Parade in 1912.

In 1908 when Allen was 15, one of his horses went missing. Not long afterwards some friends of his, who had recently moved to the Trochu district, recognized the horse when it was sold to their neighbour. They told Allan who got in touch with the Northwest Mounted Police. They sent him from Calgary to Olds by train then on to Trochu by stagecoach to identify the horse. Allan stayed overnight at the NWMP barracks, and the next day he rode his pony back home to Calgary, a distance of about 100 kms.

Allan enlisted with the 12th Canadian Mounted Rifles regiment in January 1915, and took his preliminary training at the Victoria Park horse barns, and then at the Sarcee Camp in Calgary where the regiment was housed in tents.

Allans Father, Harry Church, joined the army in Oct 1915 with the 50th Battalion and was sent overseas the following year. Allan’s brother Ernie enlisted in Nov 1915 with the 10th Battalion, Canadian Engineers and was sent overseas in March 1916. After training at Bramshott, Ernie arrived in France in Aug 1916.

Allan's regiment, the 12th C.M.R.'s, were sent overseas in June of 1915 where they trained at Bramshott, England. In early 1916 they were sent across the Channel to France where the regiment was taken on strength with the 2nd C.M.R.'s to make up a battalion.

In August 1916 Allen began training with the 2nd Army Sniping School. Snipers and spotters worked together in teams. One of Allan's spotters, Ollie Olsen, who became a good friend, later lost his life at Vimy Ridge. Allan was affectionately known as "Brud" (Brother) by his buddies.

By good fortune, Allen and his brother Ernie were reunited with their Father Harry in France in early 1917, just before the Battle of Vimy Ridge.

Allan and his regiment fought in many of the bloodiest battles of the war, including the Somme, Ypres, Hooge Crater, Sanctuary Wood, Courcelette, Mouquet Farm, Vimy Ridge, and Passchendaele. In October 1917, he was wounded in the leg by a burst of shrapnel during the battle of Passchendaele.

After being wounded he was evacuated back to England and hospitalized in Birmingham, then sent to Epsom, Surrey to convalesce. While he was recovering at Epsom he got the idea to apply for a transfer to the Air Force. He said later that he thought being in the air over the battlefield would be far better than fighting in the trenches.

Not long afterwards his transfer was accepted and he was soon on his way to Egypt to join the Royal Flying Corps.

In January of 1918 he travelled by rail through France and Italy and then across the Mediterranean by ship to Alexandria. He received his preliminary training at Cairo and his flying instruction at Shallufa on the Suez Canal. He was later stationed at Aboukir near Alexandria.

The planes he flew were Avro Trainers, and he soon learned that pilots not only had to fly their planes, they had to maintain them as well. This included fixing engines, broken struts, and sewing tears in the canvas wing. In 1918 Allan was commissioned to the rank of Second Lieutenant. He continued to train during the hot Egyptian summer but before he could go into battle as a pilot, their unit received word in November 1918 that the war was over.

He was discharged from the RAF in February 1919, but was told they wouldn’t be going back to England for several months. So Allan and some of his fellow aircrew used their time travelling around Egypt, Palestine and Iraq, before finally heading back to Canada in October 1919.

After the war, Allan and his brother Ernie took up land under the Soldier Settlement Board near Hesketh, Alberta which they homesteaded for many years. In Oct 1920, Allan married Alice Rowlinson.

In 1922 Allan contracted to deliver the mail from Redland to Hesketh. He drove a team and buggy in the summer and a sleigh in the winter. It was a 36 mile round trip. In later years he drove a car to do the route. Alan was one of the original members of the Alberta Wheat Pool and became Councillor for Kneehill Municipal District in 1954.

In 1962, Allan and his wife travelled to Britain and Europe for the summer, where they spent time with relatives and revisited some of the First World War battlefields he had fought in almost fifty years earlier.