1914 –15 was a learning curve for the British Army and the K.O.Y.L.I. There were many casualties on both sides, and by the end of 1915 most of the small original British Expeditionary Force sent to fight in France had been wiped out. The 1st and 2nd K.O.Y.L.I., involved in the key battles at the beginning of the war, had suffered significant losses. 2nd K.O.Y.L.I. lost 600 men in the Battle of Le Cateau alone.Throughout 1915 they were replaced in the trenches by part-time territorial soldiers and later, ‘Kitchener’ volunteers. These volunteers had no previous military experience, and little training.
By the middle of 1915 stalemate had been reached on the Western Front. Both sides were dug deeply into trenches. Neither side understood how best to fight this war, where the only movement had to be forward. New weapons such as gas and flamethrowers were introduced to make progress against the enemy, and increasingly heavy guns were used. In the last months of 1915, 1st K.O.Y.L.I. was part of an expeditionary force sent to Salonika in Greece. Other troops were sent to Gallipoli and Mesopotamia (Iraq) in response to the impossibility of progress in the trenches. When none of this proved successful, it became obvious that the war would have to be won on the Western Front. That would mean more men, more guns and more munitions. The country would have to wage Total War.