Muawiyah had sent an army under his son Yazid against the Roman Empire as early as 668.
Yazid, reachingas far as Chalcedon, hasd taken the important imperial center Amorion.
Although the city had been quickly recovered, the Arabs had next attacked Carthage and Sicily in 669.
In 670, the Arabs had captured Cyzicus and established a base from which to launch further attacks into the heart of the Empire.
Their fleet captured Smyrna and other coastal cities in 672.
Finally, in 672, the Arabs sent a large fleet to attack Constantinople by sea.
While the emperor, Constantine IV, was diverted by this action, the Slavs had unsuccessfully attacked Thessalonika.
The victories had ended in 674, however, when the first naval siege of Constantinople itself proved to be a catastrophe due to the defender’s effective use of Greek fire, invented around 670 in Constantinople by Kallinikos (Callinicus), an architect from Heliopolis in the Roman Iudaea Province.
Twentieth-century British chemist and historian James Partington will posit that "Greek fire was really invented by the chemists in Constantinople who had inherited the discoveries of the Alexandrian chemical school".
Many accounts note that the fires it caused could not be put out by pouring water on the flames—on the contrary, the water served to intensify or spread them, suggesting that 'Greek fire' may have been a 'thermite-like' reaction, possibly involving a quicklime or similar compound.
Others have posited a flammable liquid that floated on water, possibly a form of naphtha or another low-density liquid hydrocarbon, as petroleum was known to Eastern chemists long before its use became widespread in the 1800s.
