The State Archives of 2300 BC unearthed by Paolo Matthiae and his team. Among a huge amount of different cuneiform tablets is the earliest known peace treaty between the state-city Ebla and Abarsal an vasal kingdom of Ebla. The form of this treaty rsembles a later popular Hittite treaties - the covenant.
See:
- Stephen C. Neff, Justice among Nations, Harvard University Press 2014, p. 14
- http://www.ebla.it/escavi__gli_archivi_di_stato.html
- Amanda H. Podany, Brotherhood of Kings: How International Relations Shaped the Ancient Near East, Oxford University Press 2010, pp.29 ff