Dover Castle: Nine Centuries of Construction and Reinvention

Dover Castle's construction spanned from the 11th to the 19th century, reflecting its enduring strategic importance as the "Key to England."

• 11th Century (1066+): William the Conqueror built the first earthwork castle.
• 12th Century: Henry II replaced it with the massive stone Great Tower (Keep)—the largest in England—taking ~12 years.
• 13th Century: Added Constable's Tower, St. John's Tower, and expanded walls.
• 14th–15th Centuries: Outer Ward and additional towers strengthened defenses.
• 19th Century (Napoleonic Wars): Major modernization: new barracks, tunnels, and the South Front entrance.

Each era left its mark, creating a layered fortress that guarded the shortest sea crossing to Europe for nearly a millennium.