Lord Kitchener was one of the few people in 1914 to realise that the First World War was not going to be a short one; he believed that it would last three years and would require an army of 70 divisions.
This rigid structure did not take account of the differing ability of regiments to raise troops based upon the population of their recruiting areas.
Therefore, the Third New Army (K3) had a much higher proportion of battalions from the more populous north of England, notably Cheshire, Lancashire, Yorkshire, Durham and Northumberland.
Originally formed into the 30th – 35th Divisions, these were broken up so the battalions could train recruits and send drafts to the first three New Armies.
These units were recruited on a more narrow basis than usual, such as men who worked in a specific occupation or at a certain business, and were popularly known as "pals battalions".