Battle of Marathon
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.