The Artaxiad dynasty ruled the Kingdom of Armenia from 189 BC until their overthrow by the Romans in 12 AD. It was founded by Artaxias I, who claimed kinship with the previous ruling dynasty of Armenia, the Orontids. Their realm included Greater Armenia, Sophene and, intermittently, parts of Mesopotamia. Their main enemies were the Romans, the Seleucids and the Parthians, against whom the Armenians conducted multiple wars. Under the Artaxiad king Tigranes the Great, the Kingdom of Armenia reached its greatest territorial extent, extending for a brief period from the Caspian to the Mediterranean Sea.