The oldest parts of the Castle were built between 1066 and 1074, during the reign of William the Conqueror. There were additions over several centuries. Later, in the late 18th century, Thomas Telford remodelled the interior as a private house. The Castle was acquired by the Corporation of Shrewsbury in 1924 through the generosity of Shropshire Horticultural Society. The Castle houses the spectacular collections of the Shropshire Regimental Museum Trust including pictures, uniforms, medals, weapons and other equipment from the 18th Century to the present day.