The Metropolitan Asylums Board or Board of of the Metropolitan Aslum District, also referred to as the MAB/M.A.B., was an authority entrusted with the building and management of large infirmaries and institutions for the treatment of the sick poor of the entire London area. It was funded a common poor rate across the capital, and initially had responsibility for those suffering from smallpox, fever, or insanity. Established under the terms of the Metropolitan Poor Act 1867, the board was wound up in 1930, when its functions were transferred to the London County Council.