The First World War exacted a terrible human cost in Birmingham. More than 150,000 men from the city – over half of the male population – served in the armed forces of whom 13,000 were killed and 35,000 wounded. The onset of mechanised warfare also served to increase the strategic importance of Birmingham as a centre of industrial production, with the British Commander-in-Chief John French describing the war at its outset as "a battle between Krupps and Birmingham". At the war's close the Prime Minister David Lloyd George also recognised the significance of Birmingham in the allied victory, remarking how "the country, the empire and the world owe to the skill, the ingenuity and the resource of Birmingham a deep debt of gratitude". Some Birmingham men were conscientious objectors.