 Complete the following phrase:  Hannibal then marched south and won three outstanding victories. The first one was on the banks of the Trebia in December 218, where he defeated the other consul Sempronius Longus thanks to his brother Mago, who had concealed some elite troops behind the legions and attacked them from the rear once fighting Hannibal. More than half of the Roman army was lost. Hannibal then ravaged the country around Arretium to lure the new consul Gaius Flaminius into a trap, at the Lake Trasimene. He had hidden his troops in the hills surrounding the lake and attacked Flaminius when he was cornered on the shore. This 