A hundred years after conscription was brought in for the first time, the public is being asked to help commemorate all those compelled to fight in the First World War.

Conscription was introduced on March 2 1916, requiring all unmarried men in England, Scotland and Wales between 18 and 41 to join the armed forces.

The law was extended to married men two months later, and the upper age increased to 50 in 1918 as the war dragged on.

A century later, the public is being asked by the Imperial War Museums (IWM) to help complete and remember the life stories of all the 2.5 million soldiers who were conscripted on its permanent digital memorial, Lives Of The First World War.

Under the Military Service Act, most men were expected to fight in the war unless they qualified for exemption.

However, around 16,500 men refused to join up and registered as conscientious objectors on religious, moral or political grounds.

Diane Lees, director general of the IWM, said: "On the century of conscription, Lives Of The First World War will help people to learn and remember the First World War by sharing the personal stories of those who were conscripted and their experiences on the front line, as well as the experiences of conscientious objectors."

Among those whose stories are recorded in the archive is Private William George Holmes, who was rejected when he went to enlist in 1914, but was conscripted in 1916.

His mother tried to get him out of the army when his brother Augustus was killed, but failed, and he was wounded in 1918 and invalided out of the forces.

Private Eric Thomas Potten was not allowed to enlist in 1914 because of his important job as a railway clerk, but was conscripted in 1916 and served in the Tank Corps, taking part in the Battle of Cambrai.

Gerald Braithwaite Lloyd was one of four Quaker brothers from Birmingham.

His brother Alan was awarded the Military Cross for his actions in the Battle of the Somme, and his two other brothers served in France with the Friends' Ambulance Unit.

Gerald left his job in a factory when it started to make munitions for the war, and faced a tribunal after conscription was introduced for objecting to join the armed forces.

He was granted exemption from military service on condition he work for the YMCA.

IWM historian Matt Brosnan said: "The Military Service Act was hugely significant in being the first time that Britain introduced conscription.

"The Act symbolises how, by 1916, the First World War had become a total war, with mass mobilisation required to fight a war on such a huge scale," he said.

He added that almost every Briton would be affected by the war in some way.

Those conscripted in 1916 could have faced the Battle of the Somme, which saw nearly 20,000 British men killed on the first day, and a million men from both sides becoming casualties during the 141 days of the battle.