Successive occupants modernised and extended the manor house until it was described in 1790 as "a large pile of irregular half-timbered buildings, black and white, and surrounded with numerous out-houses and lofty walls."

The oldest part of the present building, however, is the hall, which is thought to date from c. 1300, a time when the Marnham's had a house in West Bromwich.

Presumably it originally extended further at each end to provide both service and private rooms, but they would have been removed in the earlier 15th century when the present cross wings were built.

The west wall of the hall was rebuilt when the oriel was added at its north end in the 16th century, and the detached kitchen block to the south-west of the service wing is of about the same date.

"[6] However as previously mentioned in the opening paragraph, the oldest part of the building is the Great Hall which was built by Richard de Marnham circa 1270.

[4] According to the will of Cecily Stanley in 1552, in the 16th and early 17th centuries, wheat and barley was being grown in the open fields, though in smaller quantities than rye and oats.

[4][3] Since 2020 it has been undergoing some archaeological excavations in the private area behind the large table at the far end of the great hall, and in the former pub manager’s house in the museums grounds.

On the death of his father-in-law, John Stanley acquired in his wife's right, the manor and estate of West Bromwich, holding it from Sir William Jervis by military service, and a rent of 22 pence per year.

Richard Shelton was made Solicitor General in 1625 by Charles I but was later pressured to resign in favour of Sir Edward Littleton.

In 1715 with the Sheltons in desperate circumstances all or most of the demesne lands were "neither set, mowed, nor grazed that year, but the product thereof rolled upon the ground".