He didn't invade Greece - he sent a punitive expedition against Athens and Eretria, both of which had supported the uprising of Miletus in Asia Minor against Persian rule. In the process, the Athenian and Eretrian forces had burnt the provincial Persian capital of Sardis. After the partial failure of this punitive expedition of 490 BCE against Eretria (captured, inhabitants enslaved) and Athens (turned back at Marathon), Darius determined to bring mainland Greece within his empire. As the mainland cities had been supporting revolts by other Greek cities within his empire (not only Athens and Eretria), he thought that, by absorbing mainland Greece, he would establish an ethnic frontier in the west. He therefore determined to bring whatever cities he could under his rule peacefully (by bribes, and promise to make a faction in a city to be rulers under his rule, ie puppets). Those who resisted would be captured, and puppet rulers imposed on them. He was temporarily diverted by an uprising in Egypt, and then died without launching the expedition. His son Xerxes began to carry it out in 480 BCE.
After Athens supported the Greek cities of Asia Minor in their revolt against Persia, and helped burn the Persian provincial capitat of Sardis, Persia decided to instal a puppet ruler in Athens to stop this external interference destabilising its empire.
An amphibious expedition was sent to capture the culprits of Athens and Eritrea. An expelled Athenian tyrant Hippias was to be installed to rule Athens. The invasion was repelled at Marathon.
Darius I in 490 BC, and his son Xerxes in 480 BC.
Xerxes I of Persia became king of Persia in 486BC and continued his father's campaigns against Greece in the Persian Wars.
The Greek-Persian war's, started because Athens and Eritrea sent ships to assist the Ionian's in separating from the Persian empire, because a divided Persia is easier to conquer. It was Darius who began preparations to attack Greece but soon after he died and his son Xerxes took over the task. This was a retaliation against Greece ( an eye for an eye), Persia was not the aggressor.
After conquering and uniting Greece Alexander went on to conquer the major countries of Asia Minor and the Middle East. Alexander defeated the Persian king, Darius III, and united the Persian Empire with Greece.
It was the campaign by King of Kings Xerxes of Persia (Achaemenid dynasty), son of Darius the Great, who followed in the steps of his father and attacked the Western fronts of the Persian Empire to expand Persia and to conquer Greece.
Persian King Darius I
King Darius I the Great.
Darius I .
Darius
The first Persian invasion of Greece was during the Persian Wars in 492 BCE. It was ordered by the Persian King Darius I to punish the city-states of Athens and Eretria.
When the Greek city-states within the Persian Empire in Asia Minor revolted in 499 BCE, mainland Greece cities Eretria and Athens sent military force to assist this Ionian Revolt. After the revolt was put down, Darius decided to punish these cities and sent an expedition. This was repelled at Marathon, so Darius decided that the only way to stop the mainland Greek city-states disturbing the peace in his empire was to bring them under control of a Persian governor. He began bribing the cities, and planned an invasion to bring the others under control, but died and the project was taken on by his successor Xerxes.
Xerxes
Xerxes son of Darius
Darius I in 490 BC, and his son Xerxes in 480 BC.
Darius the 1st and his son Xerxes the 1st .
Bribing the aristocracies of the Greek city-states in mainland Greece to accept Persian overlordship.
Darius the Great's commander Datis came to grief at the Battle of Marathon in 490 BC (First Persian invasion of Greece) .