Castles of the British Isles

It was Henry VIII who ordered the construction of a series of small coastal forts or castles during his reign. He had split with the Roman Catholic Church and was concerned that the Holy Roman emperor would launch an invasion of England.

In Sandgate in Kent a short way to the west of the modern town of Folkestone he ordered this castle to be built to a design by Stefan von Haschenperg. The pattern used was very similar to contemporary castles at Deal and Walmer. It was rounded to allow for the use of artillery, a relatively recent introduction to the arsenal of Europe's kings.

Sangatte was written as 'Sandgate' in English to provide the basis for the error, but other documentation was addressed to English-controlled Calais to clearly show that the reference was to the nearby Sangatte. There was no early Sandgate castle (William Loftie Rutton provides the full details).

Construction work commenced on Sunday 30 March 1539 and ended on Sunday 27 April 1540, in the thirtieth and thirty-first years of the reign of Henry VIII. The castle is one of the more unusual examples of its time in the fact it was not used to defend a harbour or anchorage but instead commanded the beach and the coast road towards Dover.

Various upgrades and restoration works were carried out in 1557 and 1715-1716, and by 1616 a large gun platform for ten cannon had replaced the southern bastion.

A great deal of the castle was demolished in 1806 to transform the remains into a Martello tower to watch out for potential Napoleonic French invasion. This programme of alterations was carried out along the coasts of East Sussex and Kent during 1805-1810.

Exterior surrounding walls were left standing but were lowered, and the embattled parapet was removed. A damaged seaward segment was rebuilt, resulting in a level of alteration in the contour.

The central keep was retained but was lowered by removing its uppermost story. All surrounding buildings were cleared away and the debris was used to level the ground between the outer walls and the keep.

A wide fosse was retained which was spanned by a small wooden bridge. The three passages which radiate from the keep to the three towers remained but the towers were removed, apart from their lowest portions which now are underground. The medieval guns were replaced with contemporary firepower.

The sea caused serious damage (and not for the first time) when the castle was flooded in 1875. It was finally abandoned in 1881, now utterly outdated as a defensive position. The site was refortified with pillboxes during the Second World War, after which the castle was sold to a private owner.

All photos by P L Kessler & Val Blackwell, taken in March 2026.