Did they have rules in the Romans wars?

Answer 1

There were rules which regulated the diplomatic relationship between Rome and other peoples and the declaration of war. Their observance was overseen by priests called the fetiales (singular fetial). They formed a college of priests whose task was to advise the Roman senate of foreign relations and the making of treaties and were responsible for formal declarations of war, peace and treaties. These priests also acted as ambassadors. The college was headed by the pater patratus, which also acted as its spokesman.

In the ritual of rerum repetitio, which was a request of restitution or reparations, the pater patratus. wore woollen hair-band, and announced Roman demands to other peoples. He recited pre-set phrases when he reached at the enemy's border, when he the first man across the border, when he entered the enemy's gate, and when he meet the leaders of the enemy. If the demands are not met, he threatened war within 33 days and returned to Rome to inform the senate and see whether it was decided to declare war. If war was decided, a fetial went to the border of the enemy, declared war and threw a javelin (the corniolum) with a tip dipped in blood into the enemy territory.

The fetiales were not involved only in the declaration of war. They also conducted negotiations, advised on the formulation of treaties and declared them formally.

Because the fetiales dealt with matters of law, rather than actual war, their phrases invoked Jupiter, Juno and Quirinus, but not Mars, who was the God of War. Through the rituals of the fetiales being religious, the Romans ensured the protection of the gods in their foreign relations.