The Attalid dynasty was a Hellenistic royal family that ruled over the region of Pergamon in western Anatolia from the late 3rd century BCE until the 2nd century BCE. Founded by Attalus I, the dynasty is known for its cultural and political achievements, including the establishment of Pergamon as a major center of art and learning. The Attalids were also notable for their diplomatic relations with other Hellenistic kingdoms and Rome. Under the rule of Attalus III, the last king of the dynasty, Pergamon was bequeathed to the Roman Republic in 133 BCE. This transfer marked the end of the Attalid dynasty and the beginning of Roman control over the region. The legacy of the Attalids includes significant contributions to architecture, such as the famous Altar of Zeus, and advancements in the arts and sciences.