Battle of Badr In 622, Muhammad bade many of his followers to migrate from Mecca to the neighboring city of Medina, 320 km (200 mi) north of Mecca. Shortly thereafter, Muhammad himself left for Medina. This migration is referred to as the "Hijra". The Quranic Verse 22:39 uttered by Muhammad sometime shortly after the migration permitted Muslims, for the first time, to take up arms in defence. During this period Muhammad employed three broad military strategies against the Meccans. Firstly, to establish peace treaties with the tribes surrounding Medina, especially with those from whom the Meccans could derive most advantage against the Muslims.
Battle of the Eurymedon with the decisive Athenian victory at the Battle of Marathon. Between the two invasions, Darius died, and responsibility for the war passed to his son Xerxes I. Xerxes then led the second invasion personally in 480 BC, taking an enormous (although oft-exaggerated) army and navy to Greece. Those Greeks who chose to resist (the 'Allies') were defeated in the twin battles of Thermopylae and Artemisium on land and at sea respectively. All of Greece except the Peloponnesus thus fell into Persian hands, but then seeking to finally destroy the Allied navy, the Persians suffered a decisive defeat at the Battle