The foundation of the Kingdom of Pergamum was laid when Philetaerus took control of the city in 282 BC. The later Attalids
were descended from his father and they expanded the city into a kingdom. Attalus I proclaimed himself King in the 230s BC,
following his victories over the Galatians. The Attalids ruled Pergamon until Attalus III bequeathed the kingdom to the Roman
Republic in 133 BC