As many as 250,000 boys under the age of 18 served in the British Army during World War One.
Fergal Keane remembers the sacrifice they made.
War confers many things on boys who pick up a weapon to fight. They learn the true meaning of fear. They test their own capacity for courage and the limits of human endurance, physical and mental.
Some find that killing comes easily to them, too easily. And others recoil from acts of blood.
But what unites all teenage warriors is the speed with which they are hurled into a place of maiming and death.
Describing the training of a boy soldier in World War One, Wilfred Owen, wrote in Arms and the Boy:
Let the boy try along this bayonet-blade
How cold steel is, and keen with hunger of blood;
story continues …http://www.bbc.co.uk/news/magazine-29934965