The title King of Syria and Queen of Syria appeared in the second century BC in referring to the Seleucid kings who ruled the entirety of the region of Syria. It was also used to refer to Aramean kings in the Greek translations of the Old Testament; mainly indicating the kings of Aram-Damascus.
Following the defeat of the (Ottoman Empire) in World War I, the region came under the rule of France, United Kingdom and prince Faisal of Hejaz who was proclaimed King of Syria on 8 March 1920. Faisal's reign lasted a few months before he was overthrown by France and the title fell out of use.
The term "Syria" was first applied by Herodotus in the 5th century BC to indicate a region generally extending between Anatolia and Egypt. With the advent of the Hellenistic period, Greeks and their Seleucid dynasty used the term "Syria" to designate the region between the Mediterranean and the Euphrates. The usage of the name in referring to the region during the Iron Age (ended 586 BC) is a modern practice.
The Seleucid king Antiochus III the Great defeated the Ptolemaic Kingdom in the Battle of Panium (200 BC); he annexed the Syrian lands controlled by Egypt and united them with his Syrian lands, thus gaining control of the entirety of Syria. Starting from the 2nd century BC, ancient writers, such as Polybius and Posidonius, began referring to the Seleucid ruler as the king of Syria. The evidence for this title's usage by the kings is provided by the inscription of Antigonus son of Menophilus, who described himself as the "admiral of Alexander, king of Syria" (Alexander refers either to Alexander I Balas or Alexander II Zabinas).