Greece was spared further invasions when an unplanned interbellum (490–480 BC) occurred due to an insurrection in Egypt in 486 BC and Darius' illness and death that year. By 480 BC, Darius' successor, his son Xerxes I (485–465 BC) had amassed a huge army, and marched into Europe by crossing the Hellespont by means of pontoon bridges, meeting and defeating the Greeks at the Battle of Thermopylae later that year and razing Athens. However, the loss of the Persian fleet at the Battle of Salamis gave command of the sea to the Greeks, and Xerxes retreated back to Asia. The following year (479 BC) the Greeks won a decisive land victory at Platea in which Mardonius was also killed, followed by another naval victory at Mycale. Greece then went on the offensive, capturing Byzantium and Sestos and thus controlling the Hellespont.