Why did Britain need to increase the size of it’s army quickly?
When war broke out in 1914, the British government expected hopefully it would be over by Christmas! The British did not expect to fight a land based European war. Britain expected to fight at sea and thought the land fighting would be done by France and Russia.
The British government were shocked to be told by Marshall Lord Kitchener that it would take a million men and three years to defeat Germany.
The British Expeditionary Force (BEF) This was the title of the forces given to the British army sent from Britain to fight in France and Belgium in the opening months of WW1. In comparison to the other countries the BEF was tiny. It went in August 1914 and by the end of the year it had taken heavy casualties.
Britain's problem They had to train and equip a whole new army quickly so they could replace the BEF.