A great force, his son-in-law Mardonius entered Macedonia, and obtained complete possession of that province and of several others upon its border; but disaster at sea, and a destructive attack by the Thracians detracted from the renown and advantage of the expedition.

A second attempt upon Athens, resulted in a total defeat of the Persian forces by the Athe- nians under the command of the famous Miltiades, upon the plains of Marathon.

This engagement, than which none in the annals of wiiriure has been more universally celebrated, occurred on the 29th day of September (B C 490).

In the midst of immense preparation to repair the losses and dis- honour thus incurred, the crown devolved upon Xerxes I.

By the death of his father, in the year B C 485.