The ancient city of Carchemish straddles a border: between the turkish Karkamis and the syrian Jerablus Tahtani. The name stuck in that of the Turkish town.
The city is mentioned during the 3rd millennium BC in the archives of Ebla. In those of Mari in the 18th century BCE, the Karkemis country is placed at the same level as those of Hassum, Ursum, Qatna and Yamhad. A prince or a king was at his head. Carchemish is then a shipping center of wine, of wood and non manufactured or manufactured products. Thus the tablet A 2407 mentions 200 tree trunks cut into planks, arranged in rafts, parked at Karkemis waiting a boatman who knows the art of driving, for a shipping to Mari with 60 men.
In the archives of Hattusa, the history of Carchemish is best known during the reign of Suppiluliama. He installed there his son, and that was the beginning of an important regional capital. It was during this conquest that occurred exchanges of letters and ambassadors with a view to give a husband to an Egyptian queen who had none. Here is a site that shows the Hittite texts during this period:
The Ugarit archives showed that Karkemis was northern Syria's decision center in the second part of the 2nd millennium BC.
At the fall of Empires Hittites and Egyptians, the ruling dynasty has kept a Neo-Hittite kingdom until 717 BC, when it was incorporated into the Assyrian empire.
The site has been occupied since the Neolithic, the English excavations have only uncovered the remains of the Neo-Hittite period.
My notes of veracity :
The site of Karkamis / Jarablus Tahtani was the ancient city of Carchemish: 5/5