Early History

The Marlborough Mound (some 20 metres high and about 100 metres in diameter at its base) is the oldest landmark in the College grounds.  

The Mound is roughly contemporary with the still larger Silbury Hill, some five miles to the west of Marlborough and around 4,500 years old. Then, from 1068 the Normans started to build a castle here, digging a moat to surround the Marlborough Mound and a large area to the south of it. The castle reached the peak of its importance in Henry III's time, Parliament enacting “The Statutes of Marlborough” there in 1267.

Although the castle (having no further military significance) was allowed to decay, its estate stayed in Royal hands until the time of Henry VIII.  When the latter married Jane Seymour the estate was given to Jane's brother, Edward, who became the 1st Duke of Somerset.

Successive members of the Seymour family lived in a house which the family built close to the site of the old castle.  At the end of the 17th Century the 6th Duke of Somerset, having acquired Petworth House in Sussex through marriage, moved there with his wife and, in due course, demolished the old Seymour house at Marlborough in which he had grown up.

By 1711 the Duke had built another house on the old Marlborough site which he gave to  his son, Algernon, Lord Hertford, and the latter moved into it in 1718, shortly after his marriage to Frances Thynne of Longleat.

The Hertfords lived happily at Marlborough, raising two children and with Lady Hertford creating a fine garden to the south of a Grotto which she had constructed at the foot of the Mound. 

With the death of Lord Hertford (later, the 7th Duke of Somerset) in 1750, the old house at Marlborough was leased out as a very fashionable coaching inn which served the gentry flocking from London to Bath at the peak of its fame.  Over the next ninety years, famous visitors at the Castle Inn included Prime Minister William Pitt (Lord Chatham) and the Duke of Wellington.

The building of the railways in the early 1840s led to the rapid demise of the coaching business and the Castle Inn closed in January 1843, prior to the foundation of Marlborough College.