Haggai and Zechariah the prophets began preaching after Nehemiah was sent back to Persia and the work on the Temple and the city was halted. After the death of Artaxerxes and two years into the reign of his son, Darius the Persian (Xerxes), they preached the word of God to the Jews; and the aging Zerubbabel and Jeshua, as examples before the people, led them to begin rebuilding the Temple and the city walls (Ezra 5:2). They were challenged by their local gentile rulers in Ezra 5:3. Notice the words of the gentiles:
Ezra 5:9: “Who commanded you to build this House and to make up these walls?”
Immediately the governor, Tatnai, wrote to Darius the king to let him know that the building of the Temple and the walls had resumed. He also requested that a search be made of the king’s treasure house in Babylon for a decree made by Cyrus concerning the building going on at Jerusalem.
Two things need to be mentioned concerning Tatnai’s letter to the king. That is, that both the Temple and the walls were in the process of being rebuilt at the same time and at this late date.
According to traditional understanding, the ‘Darius’ in chapter five of Ezra is Hystaspes; and these things occurred in the second year of his reign. Nevertheless, this is impossible. It states in this Scripture that the walls were being built up (Ezra 5:9), yet we know from Nehemiah chapter two that twenty years into the reign of the king that tradition says was Hystaspes’ grandson, that the walls were scattered all about the city and into the Kidron and Hinnom valleys (Nehemiah 1:1-3; 2:1-6). Not only had nothing been done on the walls when Nehemiah arrived but he couldn’t even pass through the city on horseback (Nehemiah 2:11-15). If the Temple and the walls were resumed in the second year of Darius and completed in his sixth year (Ezra 6:15), how could this Darius be Hystaspes when tradition says the walls were broken down and a reproach to all the Jews in the reign the one tradition says is Darius’ grandson (Nehemiah 1:1-3)?
Now if Scripture is true and worthy of our trust, then man, and especially we who claim God as our Lord, must adjust our understanding and humble ourselves to bring our thinking in line with Scripture. The two cannot be correct. Either tradition is true and the word of God is not trustworthy, or our thinking regarding these two kings and what was done in their reigns must change, so that Scripture can be magnified to the praise of God.
If this Darius is, as I suggest, Xerxes, the son of Hystaspes, then this proves the walls were not finished in fifty-two days, because Nehemiah both began and finished the rebuilding of the walls and set the gates in place (Nehemiah 7:1) immediately before their dedication. Therefore, neither the walls nor the Temple were completed in the reign of Hystaspes. Both were completed in the reign of one king, and this has to be Xerxes the son of Hystaspes and is known in Scripture by the titles of Darius the Persian (Ezra 5 & 6; cp. Nehemiah 12:22); Artaxerxes (Ezra 7 cp. Ezra 6:14) and Ahasuerus (Esther).
 See International Standard Bible Encyclopedia; Fausset’s Bible Dictionary; Smith’s Bible Dictionary and Easton’s Bible Dictionary.