When the Celts came into contact with the Romans, they changed their manner of warfare to a more organized defense against a larger army. The Celtic method of warfare was to stand in front of the opposing army and scream and beat their spears and swords against their shields. They would then run headlong into the opposing army and screamed the entire way— this often had the effect of scaring the opposing soldiers who then broke into a run; fighting a fleeing army is relatively easy work. If the opposing army did not break ranks, the Celts would stop short of the army, return to their original position, and start the process over again.