In the 16th. century King Henry VIII faced with enemies in France and Spain built a chain of coastal defences along the South Coast from Cornwall to the River Thames. The deepwater haven of the Fal Estuary along with the Port of Penryn were protected by the twin fortifications of St. Mawes and Pendennis. A third castle intended for Trefusis Point was never built. From these superb vantage points a constant guard against enemy ships was maintained. Completed in 1543, A garrison was stationed here and Pendennis Castle became a focus for military activity in Falmouth which was to last for more than 400 years. During the Civil War in 1646, the Castle fell under seige from the Roundheads. Royalists held out for nearly 6 months under the octogenarian Sir John Arundell. The Castle, along with its counterpart across the water, played its part during both World Wars; Pendennis Castle being used as a naval military HQ during World War Two. In times of peace, the castle was used by the Militia until 1908 after which it was used by the Territorial Army. Today the Castle is popular with sightseers who come to catch a glimpse of a soldiers life in Tudor Cornwall or simply to enjoy the spectacular views over Falmouth and its surrounding area.