Next to nothing is known of Nahum. Like his three-chapter book, the man is obscure. It's unfortunate, especially since his message is so directly linked to the most popular of the minor prophets: Jonah. Nahum’s message is addressed to the descendants of the same people who were evangelized as a result of Jonah’s ministry—the people of Nineveh.
One hundred years after Jonah’s visit, Nahum wrote to the next generations living in Nineveh, announcing judgment because those who had been converted in Jonah’s time had refused to pass on to their children and grandchildren (the people of Nahum’s day) the knowledge and fear of the true God. Negligence led to this terrible consequence. The result? God had to destroy such an apostate people.