 However, the Arcadian confederacy come to the assistance of the Triphylians.In 366 BC hostilities broke out between them, and though the Eleans were at first successful, they were soon overpowered; their capital very nearly fell into the hands of the enemy, and the territory of Triphylia was permanently ceded to Arcadia in 369 BC.Unable to make head against their opponents, they applied for assistance to the Spartans, who invaded Arcadia, and forced the Arcadians to recall their troops from Elis.