the persian empire attacked greece by both land and sea
First Persian invasion of Greece In the spring of 492 BC an expeditionary force, to be commanded by Darius's son-in-law Mardonius, was assembled, consisting of a fleet and a land army.[39] Whilst the ultimate aim was to punish Athens and Eretria, the expedition also aimed to subdue as many of the Greek cities as possible.[39][40] Departing from Cilicia, Mardonius sent the army to march to the Hellespont, whilst he travelled with the fleet.[39] He sailed round the coast of Asia Minor to Ionia, where he spent a short time abolishing the tyrannies that ruled the cities of Ionia. Ironically, since the establishment of democracies had been a key factor in the Ionian Revolt, he replaced the tyrannies with democracies.[39]
Battle of Marathon The Battle of Marathon (Greek: Μάχη τοῦ Μαραθῶνος, Machē tou Marathōnos) took place in 490 BC, during the first Persian invasion of Greece. It was fought between the citizens of Athens, aided by Plataea, and a Persian force commanded by Datis and Artaphernes. The battle was the culmination of the first attempt by Persia, under King Darius I, to subjugate Greece. The Greek army decisively defeated the more numerous Persians, marking a turning point in the Greco-Persian Wars.