The Thracian kingdom, also called the Sapaean kingdom, was an ancient Thracian state in the southeastern Balkans that existed from the middle of the 1st century BC to 46 AD. Succeeding the Classical and Hellenistic era Odrysian kingdom of Thrace, it was dominated by the Sapaean tribe, who ruled from their capital Bizye in what is now northwestern Turkey. Initially only of limited relevance, its power grew significantly in the ancient Roman world as a client state of the late Roman Republic. After the Battle of Actium in 31 BC, Octavian (later emperor Augustus) installed a new dynasty that proved to be highly loyal and expansive. Conquering and ruling much of Thrace on behalf of the Roman Empire, it lasted until 46 AD, when Emperor Claudius annexed the kingdom and made Thracia into a Roman province.