Aqua Claudia was an ancient Roman aqueduct that, like the Aqua Anio Novus, was begun by Emperor Caligula in 38 AD and finished by Emperor Claudius in 52 AD. It was the eighth aqueduct to supply Rome and together with Aqua Anio Novus, Aqua Anio Vetus and Aqua Marcia, it is regarded as one of the "four great aqueducts of Rome".