Jer 1:2

“Jeremiah, like Isaiah, is one of the major prophets, not of the minor, like the others from whose writings I have just given extracts. He prophesied when Josiah reigned in Jerusalem and Ancus Martius at Rome, when the captivity of the Jews was already at hand; and he continued to prophesy down to the fifth month of the captivity, as we find from his writings. Zephaniah, one of the minor prophets, is put along with him, because he himself says that he prophesied in the days of Josiah; but he does not say till when. Jeremiah thus prophesied not only in the times of Ancus Martius but also in those of Tarquinius Priscus, whom the Romans had for their fifth king. For he had already begun to reign when that captivity took place.”

“King Josiah's father was Amon, an impious man. His grandfather was Manasseh, who had instructed Josiah's father in his impiety. Josiah, on the contrary, went the exact opposite of them, siding with the party of the godly. His children, however, showed no interest in their father's virtue and imitated their forefathers' godlessness. Knowing this in advance, therefore, the God of all elected the prophet in the thirteenth year of Josiah's reign and commanded him to foretell the calamities that would befall both city and people.”