The creation of the Hartlepool Museums and Heritage Service was mainly down to one man: William Cresswell Gray, who was a member of a family of shipbuilders who played an important part in the history of Hartlepool. He left the original museum building to the town in 1920 in thanks for the safe return of his son from the First World War. The building was named the Gray Art Gallery and Museum in his honour.
Since the museum opened an important and diverse collection of objects that reflect the history of Hartlepool have become part of the museum collection. This collection includes objects of archaeology; natural history; costume; fine and decorative art; social history; world cultures; coins and medals. The museum service continues to collect today looking to fill gaps in its existing collection and represent the more recent history of the town since the amalgamation of the two Hartlepool Boroughs in 1967.