In 1915, at the height of World War I, Albert Marr swore allegiance to Britain. Going to the front, Marr asked for only one thing - to take home pavilion Jackie with him.

On the front, the soldiers do not have fun, and no one would have had an affair with the ordinary monkey, if not the amazing manner of behavior and exceptional character of Jackie, thanks to which he turned from an ordinary pavilion to a talisman of the 3rd South African Infantry Regiment. He was even given a special uniform and headdress with a distinctive sign of the infantry regiment. Jackie was a real infantry officer and instead of sitting in a blind, he took part in battles, crawling through the tranches. Pavian learned to pay tribute to senior officers, use a fork and knife as intended, and smoke tobacco in a pipe for the uniforms.

Later, an inseparable pair was sent to crush the Turks and Germans, where Jack's natural abilities were very useful, for example, he could detect the enemy at a much greater distance than the human sight allowed, which repeatedly saved the soldiers from the unexpected outbursts of the enemy.

In 1916, in the Battle of Agagia, Albert was wounded and Jackie began licking his wound until the doctors arrived. In 1918, in the Battle of Paschendale, Jackie himself was wounded. The squadron fell under heavy shelling and through the smoke rising from the bullshit of guns, one could see Jackie trying to build a primitive defensive structure of debris and stones. Shrapnel injured his right leg, which had to be amputated. Dr. Woodsend, who performed the operation, made this record in his diary:
“We thought to give the patient a chlorine form: if he died, it would be better to die under anesthesia. Never before in my practice had I given an anesthetic to such a patient. But Jackie took out a glass of anesthetic and began to drink greedy, as if it was a bottle of whisky! That was enough to amputate and get everything in order.”

At the end of the First World War, Capral Jackie - a cavalier of the "Pretorian medal", the owner of the golden blanket for injury, three blue chevrons - for each year of military service and military retirement, took part in the London Parade of Victory, sitting riding on a lavender.