Meanwhile, Eumenes II of Pergamum appealed to Rome for help against the Seleucid king Antiochus III. Flamininus was sent to negotiate with him in 192 BC, and warned him not to interfere with the Greek states. Antiochus did not believe Flamininus had the authority to speak for the Greeks, and promised to leave Greece alone only if the Romans did the same. These negotiations came to nothing and Rome was soon at war with Antiochus. Flamininus was present at the Battle of Thermopylae in 191 BC, in which Antiochus was defeated.