Ezra 1 (the Edict of Cyrus) and Ezra 2 (the list of returnees) are presented as Persian documents; Ezra 3–6, which contains further supposed Persian documents mixed with third-person narrative, may be based on the prophetic works of Haggai and Zechariah, who were active at the time; Ezra 7–10, partly in the first-person, is sometimes called the "Ezra Memoir", but has been so heavily edited that the source, if it exists, is very difficult to recover.[1]: 313 There is widespread agreement that a genuine memoir underlies Nehemiah, although it has clearly been edited.[1]: 320 It can be no earlier than about 400 BCE, but is probably later, possibly even as late as 336–331 BCE (the reign of Darius III, the last Persian king); it probably circulated as an independent document before being combined with Ezra.[1]: 320