Joel was probably a resident in Judah, as his commission was to that people. He makes frequent mention of Judah and Jerusalem (1:14; 2:1, 15, 32; 3:1, 12, 17, 20, 21).
He probably flourished in the reign of Uzziah (about B.C. 800), and was contemporary with Amos and Isaiah.
The contents of this book are,
(1.) A prophecy of a great public calamity then impending over the land, consisting of a want of water and an extraordinary plague of locusts (1:1-2:11).
(2.) The prophet then calls on his countrymen to repent and to turn to God, assuring them of his readiness to forgive (2:12-17), and foretelling the restoration of the land to its accustomed fruitfulness (18-26).
(3.) Then follows a Messianic prophecy, quoted by Peter (Acts 2:39).
(4.) Finally, the prophet foretells portents and judgments as destined to fall on the enemies of God (ch. 3, but in the Hebrew text 4).
Initial text from Easton's Bible Dictionary, 1897 -- Please update as needed