Micah was a contemporary of Isaiah. Jeremiah notes that it was Micah’s preaching influenced the reforms of Hezekiah. It is from Micah that we have the prophecy that the Messiah will come from Bethlehem (Micah 5.1ff):

“But you, Bethlehem-Ephrathah, too small to be among the clans of Judah, from you shall come forth for me one who is to be ruler in Israel; whose origin is from of old, from ancient times. Therefore the Lord will give them up, until the time when she who is to give birth has borne, and the rest of his brethren shall return to the children of Israel. He shall stand firm and shepherd his flock by the strength of the Lord, in the majestic name of the Lord, his God; and they shall remain, for now his greatness shall reach to the ends of the earth; he shall be peace.”

Micah also railed against the corruption of the priests, the cruelty of the rich, and the failure of those in authority to properly exercise social care and justice.

Not bad for one of the smallest books in the Bible, from a prophet we know almost nothing about.