 The area was part of the Etruscan civilization until the arrival of the Celts, who held it from the 6th century BC until their defeat by the Umbri in 283 BC.In 268 BC at the mouth of the Ariminus (now called the Marecchia), the Roman Republic founded the "colonia" of Ariminum.The city was involved in the civil wars but remained faithful to the popular party and to its leaders, firstly Gaius Marius, and then Julius Caesar.