If you mean the angel of Mons, practical the story is a perfect example of how legends are born and become "truth" when people want and need to believe in them in times of stress.
On 22–23 August 1914, the first major engagement of the British Expeditionary Force in the First World War occurred at the Battle of Mons. Advancing German forces were thrown back by heavily outnumbered British troops, who suffered heavy casualties and, being outflanked, were forced into rapid retreat the next day. The retreat and the battle were rapidly perceived by the British public as being a key moment in the war. Despite the censorship going on in Britain at the time, this battle was the first indication the British public had that defeating Germany would not be as easy as some had thought.
On 29 September 1914 Welsh author Arthur Machen published a short story entitled "The Bowmen" in the London newspaper The Evening News, inspired by accounts that he had read of the fighting at Mons and an idea he had had soon after the battle. He set his story at the time of the retreat from the Battle of Mons in August 1914. The story described phantom bowmen from the Battle of Agincourt summoned by a soldier calling on St. George, destroying a German host.
Machen's story was not, however, labelled as fiction
A month or two later Machen received requests from the editors of parish magazines to reprint the story, which were granted. In the introduction to The Bowmen and Other Legends of the War (1915) Machen relates that an unnamed priest, the editor of one of these magazines, subsequently wrote to him asking if he would allow the story to be reprinted in pamphlet form, and if he would write a short preface giving sources for the story. Machen replied that they were welcome to reprint but he could not give any sources for the story since he had none. The priest replied that Machen must be mistaken, that the "facts" of the story must be true, and that Machen had just elaborated on a true account.
As Machen later said:
"It seemed that my light fiction had been accepted by the congregation of this particular church as the solidest of facts; and it was then that it began to dawn on me that if I had failed in the art of letters, I had succeeded, unwittingly, in the art of deceit. This happened, I should think, some time in April, and the snowball of rumour that was then set rolling has been rolling ever since, growing bigger and bigger, till it is now swollen to a monstrous size."
"— Arthur Machen, Introduction to The Bowmen and Other Legends of the War"
Around that time variations of the story began to appear, told as authentic histories, including an account that told how the corpses of German soldiers had been found on the battlefield with arrow wounds.
In "The Bowmen" Machen's soldier saw "a long line of shapes, with a shining about them." A Mr. A.P. Sinnett, writing in the Occult Review, stated that "those who could see said they saw 'a row of shining beings' between the two armies." This led Machen to suggest that the bowmen of his story had become the Angels of Mons
