In the second decade of the thirteenth century, when Genghis Khan realized that he was an old man and it was time for him to designate a successor to the Mongol Empire, which by then consisted of most of Asia and a significant part of Eastern Europe, he summoned his sons and told them the Mongolian fable of the single-headed snake and the many-headed snake.
Once upon a time there was a great cold in Mongolia and the snakes had to go inside their holes to save themselves from freezing. The multiple heads of the many-headed snake quarreled among themselves about which hole was better for finding refuge from the cold. They could not decide and the snake froze to death on the ground. The single-headed snake faced no confusion—it went immediately into one hole and survived the winter.
Genghis Khan stressed to his sons that if they and the Mongol people became divided, they would lose not just the Mongol empire but also their original homeland. He was right in stressing on the importance of unity. History tells us that the nations where people are united by a common culture and religion survive and thrive; the nations where people are divided and diverse get ripped apart by factionalism and civil wars.