Here is a story from the Buddha, so very relevant to today:

The Buddha had heard that his monks were quarreling among themselves. He told them a story:

"In Benares there was a powerful king, Brahmadatta, who went to war against Dirgheti, the king of Koshala, for he thought the kingdom of Koshala was small and an easy conquest. Dirgheti saw that resistance was useless so and he fled his kingdom and after much wandering reached Benares and lived there with his wife in a potter's dwelling. There they had a son and called him Dirghayu.

"When Dirghayu had grown up, Dirgheti thought to himself, Brahmadatta has done us great harm and will be fearing our revenge. If ever he find us, he will kill us. So he sent Dirghayu, his son, away. Dirghayu finished his education and became skillful and wise.

"But Dirgheti's former barber, who lived in Benares, saw him one day and betrayed him to Brahmadatta for a reward. Brahmadatta had Dirgheti and his queen paraded through the streets, and there, to his horror, Dirgheti saw his son. Afraid he would draw attention to himself, he called out, 'Do not look at us. Turn away. Hatred is not appeased by hatred, only by forgiveness.' Then he and his wife were executed. But when night arrived, Dirghayu took their bodies and burned them on a funeral pyre with honors.

"Hearing of this, Brahmadatta was sure that Dirghayu would assassinate him if he could. But Dirghayu had gone to the forest, where he could be alone in his sorrow. After some time he returned to Benares, and hearing there was a job in the royal elephant stable, he took it. The king overheard him singing a sad but beautiful song to the accompaniment of his lute and was so touched by Dirghayu's sweet voice that he asked the young man to join his retinue. He soon saw how wise, good-tempered, and reliable Dirghayu was and gave him a position of trust.

"The king went hunting and took Dirghayu as his only companion. He became tired and lay down with his head in Dirghayu's lap. At last, here was Dirghayu's opportunity to avenge himself for the robbery of his kingdom and his parent's deaths. He unsheathed his sword. But then he remembered his father's last words to him, that hatred can never be appeased by hatred, and he put his sword back. The king woke and said, "I dreamed that young Dirghayu was about to kill me with his sword.'

"Dirghayu laid one hand on the king's head and with other took out his sword again. 'I am Dirghayu. The time of revenge has come.'

"The king saw that he was at his mercy,and said, ' Grant me my life, dear Dirghayu. Please grant me my life.'

"How can I grant you your life when my life is in danger from you? It is you who must grant me my life.'

"And the king said, 'I will grant you your life if you will grant me mine.'

"The took each other's hands and swore to never harm each other. Out of remorse, the king gave Dirghayu back his kingdom."

The Buddha ended his story with the comment: "Now, monks, if such can be the forbearance of kings who are used to ruling with the sword, so much more must you let your light shine before the world. You, having embraced the life of a seeker, must show yourselves to be forbearing and generous. No more altercations, no arguments, no disunion, no quarrels."

Udana Sutta. From The Pocket Buddha Reader, edited by Anne Bancroft, Shambala, Boston, 2001.