Xerxes I 486-465, Artaxerxes I 465-425, Xerxes II 425-424, Darius II 424-420.

PERSIA, the country in southwest Asia between the Caspian Sea and the Persian Gulf now known as Iran. The term Persia originated from a region of southern Iran known as Persis or Parsa. The use of the name was gradually extended by the ancient Greeks and western world to apply to the whole Iranian plateau.

The First Empire
The Iranian plateau was settled about 1500 BC by Aryan tribes, the most important of whom were the Medes, who occupied the northwestern portion, and the Parsa (Persians), who emigrated from Parsua, a land west of Lake Urmia (modern Orumiyeh), into the southern region of the plateau, which they named Parsamash or Parsumash. The first prominent leader of the Persians was the warrior chief Hakhamanish, or Achaemenes, who lived about 681 BC. The Persians were dominated by the Medes until the accession to the Persian throne in 558 BC of Cyrus the Great, an Achaemenid. He overthrew the Median rulers, conquered the kingdom of Lydia in 546 BC and that of Babylonia in 539 BC and established the Persian Empire as the preeminent power of the region. He defeated King Croesus of Lydia in 546 BC, when he probably discovered the concept of money. His son and successor, Cambyses II, extended the Persian realm even further by conquering the Egyptians in 525 BC.

DARIUS I, who ascended the throne in 521 BC, pushed the Persian borders eastwards as far as the Indus River, had a canal constructed from the Nile to the Red Sea, and reorganized the entire empire, earning the title Darius the Great. Between 499 and 493 BC he crushed a revolt of the Greek Ionians living under Persian rule along the west coast of Asia Minor, and then launched a punitive campaign against the Greeks of Greece proper for supporting the rebels. His forces were defeated at the Battle of Marathon in 490 BC and Darius died while preparing a new expedition against the Greeks. His successor was:

XERXES I (Persian Khshayarsha) (c. 519-465 BC), king of Persia (486-465 BC), the son of Darius I and Atossa (fl. 6th century BC), daughter of Cyrus the Great. Ascending the throne upon the death of his father, he subdued a rebellion in Egypt, and then spent three years preparing a great fleet and army to punish the Greeks for aiding the Ionian cities in 498 BC and for their victory over the Persians at Marathon in 490 BC. The Greek historian Herodotus gives as the combined strength of Xerxes' land and naval forces the incredible total of 2,641,610 warriors. Xerxes is said to have crossed the Hellespont (modern Dardanelles) by a bridge of boats more than a kilometre in length and to have cut a canal through the isthmus of Mount Athos. During the spring of 480 BC he marched with his forces through Thrace, Thessaly, and Locris. At Thermopylae the Spartan king, Leonidas I, and his force courageously defended the narrow pass, so delaying the Persians for ten days. Xerxes then advanced into Attica and burned Athens, which had been abandoned by the Greeks. At the Battle of Salamis later in 480 BC, however, his fleet was defeated by a much smaller contingent of Greek warships commanded by the Athenian Themistocles. Xerxes thereupon retired to Asia Minor, leaving his army in Greece under the command of his brother-in-law, Mardonius, who was slain at Plataea the following year. Xerxes was murdered at Persepolis by Artabanus, captain of the palace guard; he was succeeded by his son Artaxerxes I (reigned 465-425 BC).

Artaxerxes was probably born in the reign of his grandfather Darius I, to the emperor's son and heir, Xerxes I and was his third son. He may have been complicit in the murder of Darius, Xerxes’ eldest son.

When Artaxerxes I took power, he introduced a new Persian strategy of weakening the Athenians by funding their enemies in Greece. This indirectly caused the Athenians to move the treasury of the Delian League from the island of Delos to the Athenian acropolis. This funding practice inevitably prompted renewed fighting in 450 BC, where the Greeks attacked at the Battle of Cyprus. After Cimon's failure to attain much in this expedition, the Peace of Callias was agreed among Athens, Argos and Persia in 449 BC.

Artaxerxes I offered asylum to Themistocles, who was probably his father Xerxes's greatest enemy for his victory at the Battle of Salamis, after Themistocles was ostracized from Athens.

Xerxes II was the son and successor of Artaxerxes I. After a reign of forty-five days, he was assassinated in 424 BC by his brother Sogdianus, who in turn was murdered by Darius II.

Historians know little about Darius II's reign. A rebellion by the Medes in 409 BC is mentioned by Xenophon. It does seem that Darius II was quite dependent on his wife Parysatis. In excerpts from Ctesias some harem intrigues are recorded, in which he played a disreputable part.

As long as the power of Athens remained intact he did not meddle in Greek affairs. When in 413 BC, Athens supported the rebel Amorges in Caria, Darius II would not have responded had not the Athenian power been broken in the same year at Syracuse. As a result of that event, Darius II gave orders to his satraps in Asia Minor, Tissaphernes and Pharnabazus, to send in the overdue tribute of the Greek towns and to begin a war with Athens. To support the war with Athens, the Persian satraps entered into an alliance with Sparta. In 408 BC he sent his son Cyrus to Asia Minor, to carry on the war with greater energy. Darius II died in 404 BC, in the nineteenth year of his reign, and was followed as Persian king by Artaxerxes II.