A hundred years after the faithful remnant of Jews returned to their homeland, life is grim. They have no King and they are under the rule of Persia (now Iran). The people are well versed in the books of Kings and Samuel and so now look back on that time with nostalgic eyes. It is at this moment that the Holy Spirit inspires the Chronicler to write a history of Israel and from it preach a spiritually encouraging message for the contemporary times.
There are parallels with our times, although it is a materialistic power, rather than a Persian one that has overtaken our lives.