Why was Henry VIII’s England in peril? The short answer to this is that in Henry’s desperate bid to get a son, he made three big enemies, France, Spain and the Pope. In 1538 they all ganged up against him.Henry’s response was a plan known as the “Device of the King”, which proposed to build castles, forts, defence embankments etc to protect the south coast of England. One of those castles was Pendennis Castle in Cornwall. Potential landing points and vulnerable ports were to be protected against any French and/or Spanish attack. These were the last castles built in England except for “mock” castles harking back to the past but were still part of Britain’s defences in World War two. Henry’s daughter, Queen Elizabeth I was able to use this line of defences at the time of the Spanish Armada in 1588. and for two subsequent but smaller armadas in 1596 and 1597.