After 'Black Week' in December 1899, the War Office accepted the offer of the Lord Mayor of London, Sir Alfred Newton, to raise a force (the City Imperial Volunteers (CIVs)) from among the London Volunteer units for service in the Second Boer War. The Rangers provided a detachment of one officer (Lt Brian Alt, son of Lt-Col Alt) and 26 other ranks, who served in H Company of the CIVs between February and October 1900. Lieutenant Alt was killed at the Battle of Diamond Hill on 12 June, the only officer casualty suffered by the CIVs.