the defeat at marathon was a decisive victory that marked the end of the first persian invasion of greece. the persian force retreated to asia. darius then began raising a huge new army with which he meant to completely subjugate greece. however, in 486 bc, his egyptian subjects revolted, postponing any greek expedition. after darius died, his son xerxes i restarted the preparations for a second invasion of greece, which finally began in 480 bc.