 In the 18th and 19th centuries the population density was especially high in the southeast of the county, including the East End and West End of London.From 1855 the southeast was administered, with sections of Kent and Surrey, as part of the area of the Metropolitan Board of Works.When county councils were introduced in England in 1889 about 20% of the area of the historic county of Middlesex, along with a third of its population, was incorporated into the new administrative county of London and the remainder incorporated into the administrative county of Middlesex, governed by the Middlesex County Council that met regularly at the Middlesex Guildhall in Westminster.