When was the book of Baruch written?

Answer 1

If you believe the book is authentically from Baruch ben Neriah (secretary to the Prophet Jeremiah), then it would be 5 years after the destruction of Jerusalem and the beginning of the Babylonian Exile (582 BC).

If you believe it is a book compiled from an Deutero-Isaian/Jeremian prophetic school (like if Jeremiah and Baruch had disciples who continued teaching what they had taught and then eventually compiled a book), then it could be around the Hasmonean Revolt (160s BC).

If you believe a more Historical-Critical Method of scholarship (it is essentially an anonymous book with an intro added referencing a Biblical hero), then it could be any period of Jewish history where people needed comfort (some say 200s BC, some say as late as 200 AD.) And on top of that, this school of scholarship also holds that it likely was originally 3 (or 4, if the Letter of Jeremiah is included as chapter 6) separate works (1:10-3:8, a prayer of repentance; 3:9-4:4, a Wisdom poem; 4:5-5:9, an Isaian Messianic prophecy; with 1:1-9 as the intro added later)

(Just a random addition of info: the Jewish Canon was likely not settled until roughly the same time the Christian OT Canon was settled [300s], and the Jews did not end up including Baruch. The Christians accepted it.)

Another thing that comes up is the Letter of Jeremiah. In the Greek Septuagint, Baruch and the Letter are separate books (the order of the books was Jeremiah, Baruch, Lamentations, Letter of Jeremiah, Ezekiel), and in the Latin Vulgate, the Letter is chapter 6 of Baruch (the order being Jeremiah, Lamentations, Baruch, and Ezekiel.) It was also common at the time to reference Baruch (and Lamentations) as the Book of Jeremiah (as they were thought of as one huge work)

Sorry for all the info, hopefully it was helpful