Ancient Achaea was a region in the northern part of the Peloponnese in Greece. It was known for its rich history and played a significant role in the development of Greek culture. The area was home to several important cities, including Patras and Corinth, and was part of various political alliances throughout its history. During the Hellenistic period, Achaea became a prominent member of the Achaean League, a federation of city-states that aimed to promote unity and cooperation among its members. This league was influential in resisting external threats and fostering economic growth, contributing to the region's importance in ancient Greece.