“The Saxons are coming!” Cried the Welshman who was acting as lookout. “Take up arms! Defend yourselves!”

Soon the battle started between the Saxons and the Welshmen. The two sides fought for hours. None of them could tell friend from foe as they were all dressed in very similar clothing. Welshman killed Welshman and the Saxons drove them back.
The struggle was great for the Welshmen, the battlefield bloody and they were losing ground. The Saxons would win, and Wales would be conquered by the invaders.

A nearby monk stood and watched the conflict. Being a Welshman, he wanted his countrymen to prevail. To him the problem was obvious. Fighting a battle while killing your own men is a bad idea, the Welsh needed a way to distinguish their allies from their enemies.
He looked around, saying a prayer in his head, hoping beyond hope that his god would find a way to save his countrymen.
An itch on the monk’s leg caused him to stoop to scratch it. As he lowered himself he looked at his feet, between them was a leek. There were leeks everywhere, sprouting from the ground.
The monk picked one up, inspected it and called out “Men of Wales, take a leek from the ground and place it in your cap!”

Desperately fighting against anyone within range wasn’t a strategy that worked well for the Welshmen, the idea with the leeks was odd but it was being suggested by a man of God, so they obeyed.
It worked! The Welshmen could now tell friend from foe. Knowing who to kill was half the battle for the Welsh who were a formidable fighting force when they could focus properly.
On the battle raged, many were slaughtered, and a river of blood flowed across the battlefield. The Welshmen hacked savagely at the Saxon invaders, reclaiming ground and killing until the few enemies that remained fled back to their own land.

The Welshmen had won with the help of the monk, they wished to thank him, but none could find him.
Searching the spot where the monk had stood revealed only the presence of a spring of water which no man could remember being there before.
This is the reason that the Welsh celebrate Saint David’s day on March 1st.