Nestled into a corner at the edge of the town, and flanked on two sides by sea, the redundant Yarmouth Castle has almost become lost among the outbuildings of the George Hotel. Yet 450 years ago Yarmouth Castle played an important role in affording the islanders protection against French raids. After witnessing the sinking of his beloved flagship Mary Rose in the Solent, Henry VIII wasted little time in ordering the building of Yarmouth Castle as one of a line of fortifications along the south and east coasts to prevent further intrusions.
By 1547 Yarmouth Castle had been completed, using a great deal of stone from two Hampshire monasteries recently dissolved by the King. Yarmouth Castle was of a quite different style to many of Henry's previous forts, and would have been at the forefront of 'castle' design at the time of its commissioning. Whereas earlier structures, such as Deal Castle in Kent, generally took the form of a series of concentric circular bastions with a large circular keep at the centre, Yarmouth Castle was square in plan with a pointed 'arrow-head' bastion in the south-east corner. Protecting the vulnerable area on the landward side, and allowing raking fire down the length of a moat situated along the south and east flanks, this bastion is believed to be the earliest of its kind in England.
In modern times Yarmouth Castle appears cramped and dysfunctional but this is purely as a result of the many alterations over time. Originally, Yarmouth Castle would have been entered through a doorway in the east wall, giving access to a central courtyard area, and the guns would have been mounted on ramparts above the courtyard's perimeter ranges. Accommodation blocks and provisions have always been situated along the southern perimeter wall, but these would have been far less substantial when Yarmouth Castle was first in use. The arrow-head bastion served as the kitchen and service areas.
During the late 16th/early 17th centuries, the courtyard was filled with earth to create a level gun platform and, to provide support for the extra weight, angular buttresses were built on the seaward side of the west and north walls. Other building at this time included a second storey extension with gabled roof to the 'arrow-head' bastion, and an enlargement of the Master Gunners House in the south-east corner. In 1632 further alterations were made to what it now referred to as the 'Long Room', situated in the south-west corner of the site.
Controlled by the islands Captain (or Governor), Richard Worsley, Yarmouth Castle's original armament comprised three cannon and culverins, as well as twelve smaller guns. Throughout the next 50 years several additions were made outside of the main castle to facilitate extra ordinance, including an earthen bulwark with bastions and revelins, which was constructed along the outer edge of the moat.
At the time of the English Civil War the Isle of Wight gentry were entirely Royalist, and Captain Barnaby Burley had every intention of holding Yarmouth Castle on behalf of the King. However, with only a tiny garrison under his command, he concluded that discretion was the better part of valour and surrendered Yarmouth Castle to the parliamentarians, who were to maintain a substantial garrison there until the Reformation in 1660. Ten years later the outer earthworks were removed, the moat was filled in, and a large house (now the George Hotel) was built. A new entrance was also created in the south curtain wall.
Little appears to have changed at the castle until 1813, when modifications were made to the platform parapet, and the gun rails were laid to mount the traversing platforms of four large naval guns. These guns were dismantled in 1869 and the garrison finally withdrawn in 1875. Yarmouth Castle was then used as a coastguard signalling station until 1901, and was utilised on a small scale during both world wars. In 1984 Yarmouth Castle came under the guardianship of English Heritage.