It was anciently the chief river of the Levant, also called Draco, Typhon and Axius. The last was a native form, from whose revival, or continuous employment in native speech, has proceeded the modern name ‘Asi ("rebel"), because the river flows from the south to the north unlike the rest of the rivers in the region.
The Orontes rises in the great springs of Labweh on the east side of the Beqaa Valley, very near the fountains of the southward-flowing Litani, and it runs due north, parallel with the coast, falling 2000 feet (600 m) through a rocky gorge. Leaving this it expands into the Lake of Homs, having been dammed back in antiquity. The valley now widens out into the rich district of Hamah (Hamaih-Epiphaneia), below which lie the broad meadow-lands of Amykes, containing the sites of ancient Apamea and Larissa. This central Orontes valley ends at the rocky barrier of Jisr al-Hadid, where the river is diverted to the west, and the plain of Antioch opens.
Two large tributaries from the north, the Afrin and Kara Su, here reach it through the former Lake of Antioch, which is now drained through an artificial channel (Nahr al-Kowsit). Passing north of the modern Antakya (ancient Antioch) the Orontes plunges southwest into a gorge (compared by the ancients to Tempe), and falls 150 feet (50 m) in 10 miles (16 km) to the sea just south of the little port of Samandağı (former Suedia, in antiquity Seleucia Pieria), after a total course of 150 miles (240 km).
Mainly unnavigable and of little use for irrigation, the Orontes derives its historical importance solely from the convenience of its valley for traffic from north to south; roads from the north and northeast, converging at Antioch, follow the course of the stream up to Homs where they build the Al-Rastan dam , where they fork to Damascus and to Syria and the south; and along its valley have passed the armies and traffic bound to and from Egypt in all ages. On the Orontes was fought the Battle of Kadesh during the reign of Ramesses II (1279 – 1213 BC). By the Orontes the Battle of Qarqar was fought in 853 BC, when the army of Assyria, led by king Shalmaneser III, encountered an allied army of 12 kings led by Hadadezer of Damascus. In 637 A.D the Battle of Iron bridge was fought between the forces of Rashidun Caliphate and Byzantine Empire near the Iron bridge on the river made by Romans.
The Orontes has long been a boundary marker. For the Egyptians it marked the northern extremity of Amurru, east of Phoenicia. For the Crusaders in the 12th century, the Orontes River became the permanent boundary between the Principality of Antioch and that of Aleppo.
The French writer Maurice Barrès (1862–1923) wrote about the river in his Un Jardin sur l'Oronte.