Darius the Great was one of the kings in Persia.
After Cyrus the Great’s death, a fake king took the throne of Persia. However, after a short period of time, that king was murdered by Darius, and he took the throne. He was a distant relative to Achaemenes, and used that to justify his right to the throne.
He was a strong ruler whom had achieved several great goals. However, as great as a king he was, Darius the Great was also a cold king, who had many murdered, even most of his own family members, who he suspected were to overthrow him.
Darius achieved many accomplishments, such as creating the daric (a form of currency), improved road systems for efficient trade, and organized a tax system which lead to state banking.
Darius’ religion was Zoroastrianism, but he was very accepting of other religions in the empire. He also helped the Jews rebuild the temple of Jerusalem, and he also supported Greek and Egyptian religions.
However, in 486 B.C., Darius died while preparing soldiers to fight the Greeks. The throne was soon taken by Xerxes, who helped carry on Darius the Great’s campaign against the Greeks.