The trustees of the museum joined forces with Warwickshire County Council to acquire St John's House in 1961.

Both museums were opened by Field Marshal Viscount Montgomery on 2 August 1961.

[2] The museum moved to new premises at Pageant House in Jury Street in April 2023.

[4] The museum is an Accredited museum (a national scheme run by the Arts Council), a registered charity, governed by a group of trustees, and is supported by the Ministry of Defence.

[5] In November 2020, the museum purchased at auction the Memorial Plaque of Euan Lucie-Smith of the Royal Warwickshire's 1st Battalion, one of the first mixed-heritage infantry officers in a regular British Army regiment, and the first killed in World War I, at the Second Battle of Ypres on 25 April 1915 .