The Realities of Shivat Tzion
At the end of these seventy years, Bavel's great empire indeed fell to the Persians (as Yirmiyahu had predicted - see Ezra 1:1). Koresh [Cyrus the Great], the first king of this newly founded Persian empire, issued an edict allowing the Jews to return to Jerusalem to rebuild their Temple (Ezra 1:1-6). (See Timeline.)
Despite this generous decree, the Jews were only granted religious autonomy, not political sovereignty. For example, Zerubavel - the political leader of the returning Jews - is consistently referred to as "pechat Yehuda," the governor of Judah (Chagai 1:1, 2:2). His contemporary Yehoshua ben Yehotzadak served as the Kohen Gadol (high priest).
Unfortunately, only a small portion of the exiles returned and this small population succeeded only in building the mizbayach [altar] (see Ezra 3:2-6). Attempts to begin construction of the new Temple were thwarted by the local non-Jewish population (see Ezra 4:4-5). The general situation was quite pathetic (see Ezra 3:12, Zecharya 4:8-10, Chagai 2:1-6).
Clearly, Yirmiyahu's prophecies of a grand redemption remained only partially fulfilled. Now, it became the challenge of the prophets of shivat Tzion - Chagai and Zecharya - to revive this redemption process.
Some 18 years later, as Daryavesh [Darius the Great] takes over the throne of the Persian Empire (see Timeline), a new opportunity emerges to begin construction of the Second Temple.