Corinth was also known for its philosophers. Perhaps the most outstanding was Diogenes (around 412 – 323 BCE), well known for his unorthodox approach to life. He had a decisive influence on Greek philosophy. In Richard Stoneman’s Legends of Alexander the Great we hear about a meeting of Diogenes and Alexander the Great:
A Cynic background is present in the famous story of Alexander’s encounter with Diogenes at Corinth. Diogenes was the effective founder of the Cynic school and was famed throughout antiquity for his rejection of convention, evinced in his choosing to live in a barrel and his practice of defecation and masturbation in public (like a dog, hence the name ‘cynic’). The story goes that Alexander met Diogenes and was so impressed by his wisdom that he offered him a gift; and Diogenes simply asked Alexander ‘Please stand out of my sunshine’. The philosopher’s content with the bare minimum of natural pleasure is contrasted with the world conqueror for whom no acquisition was sufficient.

The city of Corinth was sacked and destroyed by the Romans in 146 BCE, but it was rebuilt by Julius Caesar in 44 CE and regained its prominence as a provincial capital.

In the 1st century CE the religious life in Corinth took an unexpected turn. St. Paul, the famous missionary of early Christianity, arrived in Corinth to spread the Gospel. His efforts met with both resistance and acceptance, and he established a Christian community in the city. His letters to the Corinthians, preserved in the New Testament, provide valuable insights into the early Church and the challenges faced by its members.

During the Byzantine era Corinth was a major center of Christianity – now with churches and monasteries that had replaced the ancient sanctuaries and temples.

Whenever invading armies threatened to conquer the city the citizens fled to the fortificated upper city on the nearby mountain, Acrocorinth.