"My children, I am nearing the end of my life. With the help of Tengri, I leave you such an empire that it is a year's walking distance from its center to its tip. If you want to preserve it, stay united, act together against your enemies, agree to increase the wealth of those who are loyal to you. One of you must sit on the throne. Ögedei will be my successor. Respect this choice after my death."
January 1, 1970
https://en.wikiquote.org/wiki/Genghis_Khan