[2] In the medieval era it has long been believed to have served as part of both the sea and military defence for the harbour.

However, as Hartlepool went into decline Middleton gradually lost its significance; by the late 18th century half of neighbouring Victoria and Commissioners Harbour was recorded as being half-filled in and used as a cornfield.

[7] At its height in the late 19th century, the area had three shipyards and two engineering works based in Middleton.

For Middleton it was particularly hard hit by a decline, in the commission of ships built in British shipyards, as well as the fact much of the Dockyards at Hartlepool were gradually considered unsuitable for the modern container ships (until the improvements made to Central Dock, which now serves as the main port of the town).

This and a combination of the highly polluted, dirty and derelict environment of Middleton, gradually led to the site's depopulation, to a point where by the late 1980s the only inhabited part was a surviving pub.