 Complete the following phrase:  In 218 BC DXXXVI a.u.c. the Carthaginian army commander Hannibal marched troops, cavalry and African elephants across the Alps in an effort to conquer Rome by approaching it from north of the Italian peninsula. The Roman government was complacent because the Alps were apparently a secure natural obstacle to would-be invaders. In December 218 BC the Carthaginian forces defeated Roman troops, in the north, with the use of elephants. Many elephants did not survive the cold weather and disease that was typical of the European climate. Hannibals army fought Roman troops in Italy for 15 years but failed to conquer Rome. Carthage was ultimately 