Remembering History: Windsor Castle in Berkshire, UK. Windsor is the oldest, longest inhabited castle in the world. Construction began in the 11th century by William the Conqueror. It has been used as a residence by monarchs since Henry I.

Windsor Castle in Berkshire, UK. Windsor is the oldest, longest inhabited castle in the world. Construction began in the 11th century by William the Conqueror. It has been used as a residence by monarchs since Henry I.

Windsor Castle in Berkshire, UK. Windsor is the oldest, longest inhabited castle in the world. Construction began in the 11th century by William the Conqueror. It has been used as a residence by monarchs since Henry I.