With the Nemean Games, the Isthmian Games were held both the year before and the year after the Olympic Games, while the Pythian Games were held in the third year of the Olympiad cycle. The Isthmian Games were held in honour of Poseidon, and were said to have originated around 580 BC to celebrate the death of the tyrant Kypselos. Another story states that the Games were founded by Theseus.
Administration of these Games was undertaken by the city of Sicyon following the Roman destruction of Corinth in 146 BC, until Corinth recovered ownership of these Games at some point between 7 BC and AD 3. The Isthmian Games thereafter flourished until Theodosius I suppressed them as a pagan ritual.
The winners of the Isthmian Games received a wreath of pine.