Sandsfoot Castle was built as a consequence of international tensions between England, France and the Holy Roman Empire in the final years of the reign of King Henry VIII.
Traditionally the Crown had left coastal defences to the local lords and communities, only taking a modest role in building and maintaining fortifications, and while France and the Empire remained in conflict with one another, maritime raids were common but an actual invasion of England seemed unlikely.
Modest defences, based around simple blockhouses and towers, existed in the south-west and along the Sussex coast, with a few more impressive works in the north of England, but in general the fortifications were very limited in scale.

After 1533, Henry broke with popes Pope Clement VII and Paul III in order to annul the long-standing marriage to his wife, Catherine of Aragon, and remarry.
Catherine was the aunt of Charles V, the Holy Roman Emperor, and Charles took the annulment as a personal insult.
This resulted in France and the Empire declaring an alliance against Henry in 1538, and the Pope encouraging the two countries to attack England.
An invasion of England appeared certain.
In response, Henry issued an order, called a "device", in 1539, giving instructions for the "defence of the realm in time of invasion" and the construction of forts along the English coastline.

Sandsfoot Castle was built to protect the Weymouth Bay anchorage, being placed on cliffs overlooking the waterway, opposite Portland Castle on the other side.
Sandsfoot was a blockhouse, intended to defeat enemy ships using a battery of heavy artillery, and had minimal protection against an attack from the land.
It was completed by 1541, run by a captain appointed by the Crown, and cost £3,887 to build.
There was probably an early agreement that the nearby village of Wyke Regis had a responsibility to support the castle, and in exchange they came to traditionally enjoy an exemption from taxes and militia duties.
The antiquarian John Leland visited the castle soon after its construction, describing it as "a right goodlie and warlyke castle" with "one open barbican", probably referring to the castle's gun platform.

Coastal erosion quickly began to threaten the castle, causing what was reported as a "great gulf" on its seaward side, and repairs costing £383 were necessary by 1583, completed by John Wadham of Catherston, MP and Recorder for Weymouth and “Captain of the Queen’s Majestie at Sandesfoot Castle” who died in 1584.
During the invasion scare that accompanied the Spanish Armada of 1588, the normal garrison of Sandsfoot was supplemented by another 50 men.
Sandsfoot Castle was built as a consequence of international tensions between England, France and the Holy Roman Empire in the final years of the reign of King Henry VIII. Traditionally the Crown had left coastal defences to the local lords and communities, only taking a modest role in building and maintaining fortifications, and while France and the Empire remained in conflict with one another, maritime raids were common but an actual invasion of England seemed unlikely. Modest defences, based around simple blockhouses and towers, existed in the south-west and along the Sussex coast, with a few more impressive works in the north of England, but in general the fortifications were very limited in scale.
After 1533, Henry broke with popes Pope Clement VII and Paul III in order to annul the long-standing marriage to his wife, Catherine of Aragon, and remarry. Catherine was the aunt of Charles V, the Holy Roman Emperor, and Charles took the annulment as a personal insult. This resulted in France and the Empire declaring an alliance against Henry in 1538, and the Pope encouraging the two countries to attack England. An invasion of England appeared certain. In response, Henry issued an order, called a "device", in 1539, giving instructions for the "defence of the realm in time of invasion" and the construction of forts along the English coastline.
Sandsfoot Castle was built to protect the Weymouth Bay anchorage, being placed on cliffs overlooking the waterway, opposite Portland Castle on the other side. Sandsfoot was a blockhouse, intended to defeat enemy ships using a battery of heavy artillery, and had minimal protection against an attack from the land. It was completed by 1541, run by a captain appointed by the Crown, and cost £3,887 to build. There was probably an early agreement that the nearby village of Wyke Regis had a responsibility to support the castle, and in exchange they came to traditionally enjoy an exemption from taxes and militia duties. The antiquarian John Leland visited the castle soon after its construction, describing it as "a right goodlie and warlyke castle" with "one open barbican", probably referring to the castle's gun platform.
Coastal erosion quickly began to threaten the castle, causing what was reported as a "great gulf" on its seaward side, and repairs costing £383 were necessary by 1583, completed by John Wadham of Catherston, MP and Recorder for Weymouth and “Captain of the Queen’s Majestie at Sandesfoot Castle” who died in 1584. During the invasion scare that accompanied the Spanish Armada of 1588, the normal garrison of Sandsfoot was supplemented by another 50 men.
Sandsfoot Castle