all his wives. Death and succession After becoming aware of the Persian defeat at the Battle of Marathon, Darius began planning another expedition against the Greek-city states; this time, he, not Datis, would command the imperial armies. Darius had spent three years preparing men and ships for war when a revolt broke out in Egypt. This revolt in Egypt worsened his failing health and prevented the possibility of his leading another army. Soon afterwards, Darius died. In October 486 BCE, his body was embalmed and entombed in the rock-cut tomb at Naqsh-e Rostam, which he had been preparing. An inscription on his tomb introduces him as "Great King, King of Kings, King of countries containing all kinds of men, King in this great earth far and wide, son of Hystaspes, an Achaemenian, a Persian, son of a Persian, an Aryan [Iranian], having Aryan lineage." A relief under his tomb portraying an equestrian combat was later carved during the reign of the Sasanian King of Kings, Bahram II (). Xerxes, the eldest son of Darius and Atossa, succeeded to the throne as Xerxes I; before his accession, he had contested the succession with his elder half-brother Artobarzanes, Darius's eldest son, who was born to his first wife before Darius rose to power. With Xerxes' accession, the empire was again ruled by a member of the house of Cyrus. Government Organization Early in his reign, Darius wanted to reorganize the structure of the empire and reform the system of taxation he inherited from Cyrus and Cambyses. To do this, Darius created twenty provinces called satrapies (or archi) which were each assigned to a satrap (archon) and specified fixed tributes that the satrapies were required to pay. A complete list is preserved in the catalogue of Herodotus, beginning with Ionia and listing the other satrapies from west to east excluding Persis, which was the land of the Persians and the only province which was not a conquered land. Tributes were paid in both silver and gold talents. Tributes in silver from each satrap were measured with the Babylonian talent. Those paid in gold were measured with the Euboic talent. The total tribute from the satraps came to an amount less than 15,000 silver talents. The majority of the satraps were of Persian origin and were members of the royal house or the six great noble families. These satraps were personally picked by Darius