The Lancashire Militia was an auxiliary military force in Lancashire in North West England. From their formal organisation as Trained Bands in 1558 and their service in the Williamite War in Ireland and against the Jacobite Risings, the Militia regiments of Lancashire served during times of international tension and all of Britain's major wars. They provided internal security and home defence but sometimes operated further afield, including Ireland and the Mediterranean, relieving regular troops from routine garrison duties, and acting as a source of trained officers and men for the Regular Army. All the infantry battalions went on active service during the Second Boer War and all served as Special Reserve training units in World War I, with one battalion seeing considerable action on the Western Front. After 1921 the militia had only a shadowy existence until its final abolition in 1953.