premise: The Battle of the Trebia took place in the province of Piacenza.
hypothesis: The Battle of the Trebia ( or Trebbia ) was the first major battle of the Second Punic War , fought between the Carthaginian forces of Hannibal and the Roman Republic in December of 218 BC , on or around the winter solstice . It was a resounding Roman defeat with heavy losses , and yet some 10,000 and more Romans , over 2.5 legions , survived on the field and retreated in order to Placentia ( Piacenza ) . The battle took place in the flat country of the Province of Piacenza on the left bank of the Trebbia River , a shallow , braided stream , not far south from its confluence ( from the south ) with the Po river . Piacenza [ pjaˈtʃɛntsa ] ( Emilian-Romagnol : Piasëinsa , ) is a city and comune in the Emilia-Romagna region of northern Italy .