The chronologies of other cultures can be used to find links to Egypt. The most important are the Assyrian and Babylonian chronologies. Chronologies of the Hittites, ancient Palestine, and ancient Greece are also used. For example in the 18th century BC a stela of the Governor of Byblos Yantinu says that pharaoh Neferhotep I was ruled at the same time as kings Zimri-Lim of Mari and Hammurabi of Babylon. In the 15th century BC, during the Amarna Period, there are letters between the Egyptian Kings Amenhotep III and Akhenaten, and various Near Eastern monarchs.