Upon the death of Thomas Charles and in accordance with his estate, Maidstone Borough Council purchased the building in 1856 for the sum of £1,200, investing a further £300 for repairs.

[4] The Museum is recognised as having the largest mixed collections in the county and one of the most important in the south-east of England, outside London.

[9] The Egyptian collection is home to the mummified remains of Ta-Kush a woman who was born in what is now Sudan before being buried in Egypt in the second half of the 7th century BC.

[10] A new acquisition in 2009 was the kernos from Melos in Greece; it is early Cycladic III period and 4000 years old.

The collection of photographs and maps is of local importance and is complemented by over 10,000 items of printed ephemera relating to the history of Kent.

[13] There are internationally important collections of artefacts of Pacific, Oceanic and African ethnography as well as diverse material from Asia and North and South America.

They include 17th to 19th century furniture, musical instruments, toys and games, ceramics, glass, costumes and needlework, paintings, prints and drawings and sculpture.

[19] The Japanese collections of fine and decorative art material are important and amongst the most studied in the country.

They include ceramics, sword fittings, netsuke, lacquer and books as well a series of over 750 Edo-period (1600–1868) woodblock prints.

There is also a British collection of some 6,000 specimens of critical genera including Rubus, Taraxacum and Hieracium.

The main strengths of the palaeontology are the marine Cretaceous and Tertiary of Kent, especially Chalk, Lower Greensand and Lenham Beds; but also Gault and London Clay.