quality:corruption
Building projects

During Darius's Greek expedition, he had begun construction projects in Susa, Egypt and Persepolis. He had linked the Red Sea to the river Nile by building a canal (Darius Canal) which ran from modern Zaqāzīq to modern Suez. To open this canal, he travelled to Egypt in 497 BCE, where the inauguration was carried out with great fanfare and celebration. Darius also built a canal to connect the Red Sea and Mediterranean. On this visit to Egypt he erected monuments and executed Aryandes on the charge of treason. When Darius returned to Persis, he found that the codification of Egyptian law had been finished.

Additionally, Darius sponsored large construction projects in Susa, Babylon, Egypt, and Persepolis. In Susa, Darius built a new palace complex in the north of the city. An inscription states that the palace was destroyed during the reign of Artaxerxes I, but was rebuilt. Today only glazed bricks of the palace remain, the majority of them in the Louvre. In Pasargadae, Darius finished all incomplete construction projects from the reign of Cyrus the Great. A palace was also built during the reign of Darius, with an inscription in the name of Cyrus the Great. It was previously believed that Cyrus had constructed this building, however due to the cuneiform script being used, the palace is believed to have been constructed by Darius.

In Egypt, Darius built many temples and restored those that had previously been destroyed. Even though Darius was a believer of Ahura Mazda, he built temples dedicated to the Gods of the Ancient Egyptian religion. Several temples found were dedicated to Ptah and Nekhbet. Darius also created several roads and routes in Egypt. The monuments that Darius built were often inscribed in the official languages of the Persian Empire, Old Persian, Elamite and Babylonian and Egyptian hieroglyphs. To construct these monuments, Darius employed a large number of workers and artisans of diverse nationalities. Several of these workers were deportees who had been employed specifically for these projects. These deportees enhanced the empire's economy and improved inter-cultural relations. At the time of Darius's death construction projects were still under way. Xerxes completed these works and in some cases expanded his father's projects by erecting new buildings of his own.