Vindonissa (from a Gaulish toponym in windo- "white") was a Roman legion camp at modern Windisch, Switzerland. It was probably established in 15 AD. In an expansion around 30, thermal baths were added. The Legio XIII Gemina was stationed at Vindonissa until 44 or 45. With the arrival of the 21st legion (XXI Rapax) the camp was rebuilt with stone fortifications. After the 21st legion had looted the countryside in 69, it was replaced by the 11th legion (XI Claudia*) which remained stationed until 101. After this date, Vindonissa was a civilian settlement, with a castle built in the 4th century.