[7] In the 1120s Bishop Roger of Salisbury was given control over Malmesbury – both the monastery and the town – and built a castle next to the Abbey, much to the annoyance of the monks.

It was of strategic importance during the so-called Anarchy (1139–1153), a civil war between King Stephen and his cousin, the Empress Matilda.

In 1139 King Stephen came in person to Malmesbury in order to besiege and retake the castle which had been seized by Flemish freelance mercenaries.

In January 1153 the son of the Empress Matilda, Henry Plantagenet, invaded England intending to seize the crown.

The monks always resented the presence of a castle which was, according to the historian William of Malmesbury, "just a stone's throw" from the Abbey church.

In 1216 King John, the son of Henry II, was desperate for money because he was fighting a war against both baronial opponents and an invading French army.

[3] After the Dissolution of the Abbey in 1539 and the departure of the monks the building became an inn offering accommodation to travellers on the road from Bristol to Oxford.

The claim that the Old Bell is the oldest hotel in England is based, therefore, on the strong possibility that there was more or less continuous use of the building as a place of hospitality from about 1220 to the present day.

After the demolition of the castle the kings and queens of England, and their senior courtiers, lodged in the Abbey guest house, in what is now the Old Bell.

[7][11] The abbey guest house was extended at the east end in the late 15th or early 16th century and the older structure partly refaced and re-roofed.

Following the dissolution of the monasteries, the house was referred to as the Steward's Lodging and was used for some time as weavers' lodgings: "every corner of the vast houses of office which belonged to the abbaye", Leland noted in 1540, "be fulle of lumbes to weve clothe yn"[12] The present roofline and dormers date to the 17th century, and the west extension was added in 1908.

The inn has a central cross-axial stack, with a 16th-century two-bay extension and two large gable dormers on the east side.

When looking at the Old Bell from Abbey Row it is easy to see the distinct nature of Castle House which still has its own front door set within a fine 18th-century 'shell' porch.

At about the same time that the extension was built the Castle House ceased to be used as a separate dwelling and was integrated into the hotel building.

A prominent feature of the inn is an ashlar fire hood which is believed to be one of the earliest domestic-style ground-floor fireplaces, served by a flue, in England; it is dated to the initial building in 1220.

The central room to the first floor has a late 15th-century and early 16th-century compartmental ceiling with deeply moulded beams, and 17th-century dormers are cut through large trenched purlins.

Between 1748 and 1896 the Old Bell, and the adjacent Castle House, were owned by the more respectable Rushout family, who leased out the two properties on long leasehold contracts.

Soon afterwards, Moore also bought the freehold of Castle House and began the process of integrating the two properties into one hotel building.

A pioneering Malmesbury industrialist, Walter Hanks, operated a mill below The Old Bell on the River Avon in the late 1100s.

Having bought the hotel, the new owners discovered that members of the Malmesbury Hanks family owned the leasehold on part of the building in the 1860s and 1870s.