The Guildhall Library is administered by the Corporation of London, the government of the City of London, which is the historical heart of London. It was founded in the 1420s under the terms of the will of Lord Mayor Dick Whittington. It was originally housed in the Old Library at the Guildhall, and moved to modern premises elsewhere in the Guildhall complex in the 1970s.
The library is a public reference library and specialises in subjects relevant to London. The collection has its greatest depth on topics specifically concerned with the City, but also contains a great deal of material on the other parts of metropolitan London. It is divided into three main sections: printed books; manuscripts; and prints, maps and drawings. The material dates from the 11th century onwards.