It is Munich, 1919. In the second city of Germany, the corporal lay on the ground, badly beaten and he is bleeding profusely. The irate German soldiers continued to slam their jackboots into his face and body. A flash of steel indicated that bayonets had been drawn. The corporal prepared to die.

And then a volley of gunshots exploded above the heads of his attackers, echoing furiously around the gymnasium walls. As the Communist Party supporting soldiers fled the scene, the 30-year-old corporal glanced through bleeding eyes to try and identify his saviour.

Into his vision stepped eight armed men, headed up by an Irishman. By sheer chance, the corporal had served alongside him on the Western Front less than a year earlier.

The Irishman had fought for Germany in the war, married a German woman at the end of it, and joined the Freikorps, the militia formed to protect Munich from the Communists.

On this particular evening in the spring of 1919, he was in charge of the Munich barracks. He had been resting when informed that a riot had broken out in the gymnasium. As he and his brigade set out to quell the riot, the Irish soldier was informed that the catalyst for the unrest was a corporal who had unwisely attempted to woo the soldiers ahead of the upcoming municipal elections.

Once the mob had dispersed, the Irishman instructed the corporal that, for his own safety, he was placing him under arrest and taking him to the guardroom.

In 1930, the Irishman went to Nuremberg to watch one of the NSDAP rallies. That was the first time he had seen the corporal since saving his life in Munich eleven years earlier. The corporal now stood at the centre of a platform which was swathed in Swastika flags. Tens of thousands had gathered to hear him speak. The corporal’s name was Adolf Hitler.

The Irishman who saved Hitler’s life in 1919 was Michael Keogh (pictured), a policeman’s son from Tullow, County Carlow. His bravery on that chaotic night changed the course of history.