Several of its constituent units would later serve overseas, deployed for support and garrison duties in almost every theatre of the war.

The second line units also served to absorb the large number of new recruits who had joined the Territorial Force following the outbreak of war.

[2][3][4][5] The division also raised second-line Territorial artillery, medical signal and engineer units from the same areas.

[9] The 63rd began to disband in May 1916, and ceased to exist in July, with some units remaining independent for several months before being broken up or transferred to new divisions.

[9] Four battalions were posted to overseas garrison duties, the 2/7th Northumberland Fusiliers to Egypt, the 2/4th East Yorkshires to Bermuda and the 2/5th and 2/9th Durham Light Infantry to Salonika.