The Old Blockhouse, Tresco
Henry VIII built a series of fortifications along the English coast to defend against his French and Spanish enemies, but Scilly was left unprotected. During the reign of his youthful successor Edward VI (1547-53) the Old Blockhouse and King Charles’ Castle were built on Tresco (1548-50) and Harry’s Walls on St Mary’s was begun in 1551, but was never completed as the government ran out of money.
The Old Blockhouse overlooking Old Grimsby harbour was probably the earliest of the defences on Tresco. It consists of a square, paved platform that could have accommodated three guns, and the walls around it have been reduced in height. On the south side there was a built-in locker, presumably for gunpowder and attached to the west side there is a small room which was lit by two windows and heated by a fireplace. This small room would have been a welcome shelter for the garrison at this exposed site.
Around the building there is a shallow bank that could date from the mid-16th century or may date from the Civil War when the Old Blockhouse was at the heart of fighting. (See Oliver’s Battery and the Civil War on Tresco)
For information and a downloadable discussion of the Old Blockhouse visit http://www.english-heritage.org.uk/daysout/properties/old-blockhouse/
For more information on Scilly’s rich military history read Defending Scilly by Mark Bowden and Allan Brodie (English Heritage 2011 £9.99)
http://www.english-heritage.org.uk/publications/defending-scilly/