Major mint: Sardis.

The Persians were originally a subject people of the Medes. The Medes had their finest hour when they took part in a coalition which destroyed the Assyrian capital Nineveh; by the middle of the sixth century BC they were in decline. The first Achaemenid king, Cyrus II (559-529 BC), was a client king of the (to the Medes) despised Persians, who overthrew his grandfather and former master Astyages (585-550 BC).

Cyrus, called the Great, was a great conqueror, who campaigned to bring all of Asia Minor under his control. He defeated the Lydians first, taking their capital Sardis in 546 BC; he then turned against Babylon, defeating its king Nabonidus, then capturing Babylon itself from the somewhat dissipated rule of Naboniduss son Bel-Shazzar in 539 BC. Cyrus was forced to halt his conquests, however, in order to deal with the Scythians, and in the process was killed in 529. Later legend claimed that his head was placed in a bucket of blood; the idea was that he was so bloodthirsty all his life, that now his head at least could enjoy its fill.

Cyruss son Cambyses next attacked Egypt; he conquered it, but shortly thereafter went insane, and died, either by suicide or by accident, in 522 BC. His successor Darius, a relative, seized power, and gained much more territory. His attempt to conquer the Scythians proved unsuccessful, however; as did his attempt to conquer European Greece, coming to a sudden halt at Marathon in 490 BC.

Dariuss son Xerxes decided to avenge Dariuss difficulties with the Greeks by a massive invasion. His army and navy came to grief; the sea-fight at Salamis and the land battle at Platea, then another sea battle at Mycale, all in 480-79 BC, put a stop to that.

Persian power, though remaining formidable, declined slowly through the fifth century. The Persians intervened in the Peloponnesian War mainly by paying their friends, and their friends in that war were anybody opposed to Athens. The result was that Sparta replaced Athens as Persias enemy. Meanwhile Egypt revolted successfully in 405 BC; Cyrus the Younger raised a mercenary army against Artaxerxes II, and although he was defeated and killed, his army escaped; the story can be read in Xenophons Anabasis; then in 373 a disorderly coalition of satraps revolted. The revolt was suppressed, but it did not bode well for future events.

In the later fourth century the empire drowned in intrigue and faction, and the Persian kings made the major error of refusing to aid Athens against Philip of Macedon. The result, a temporarily unified Greece, bore fruit within a decade at Gaugamela and Issus, when the last Achaemenid king, Darius III Codomannus, lost two battles, his throne and his life to Alexander, son of Philip.

Achaemenid coinage is uniform. It consists of gold darics and silver sigloi and fractions. The obverse shows the king running, shooting a bow on coins of Darius I, or holding a spear and bow or dagger and bow. The coins were mostly issued at Sardis, but probably at one or two unidentified mints as well. They are frequently found with small test marks of various designs; these bankers marks on coins probably provided the prototypes for e. g. the early Indian punch-marked coinage.