During World War I the need to identify friendly troops in assaulting formations was made difficult by the new dispersion of troops across the battlefield. Beginning with the arrival of large number of Kitchener's Army troops in 1915, and widespread after the Battle of the Somme of 1916, each battalion of a division would have a particular sign of a distinctive coloured cloth patch, either sewn to the uniform jacket (on the sleeves, or the back of the tunic), or painted on the helmet. These distinguishing marks, known as "Battle Patches" were distinct from the Division signs, and were for the most part simple shapes and colours. The scheme for these Battle patches could be decided at division or brigade level or be based on regimental colours or insignia, and was in some cases continued do