Josiah, though not as well known as many persons in the Old Testament, is as compelling of a figure as you can find in the Scriptures. Knowing the time in Judah's history only adds to how impressive his life was.
Judah was well into its history and Israel in the north was long since gone. What remained of Judah was in a state of total corruption and pagan worship. All of this alongside the Jewish religious structure that remained in Judah at that time. So completely absent was the genuine worship as Scripture demanded, so God's nation as it began was completely unrecognizable. Decades of decay was not overcome by previous, brief attempts at correction.
As history records Josiah desired to repair damage through neglect of God's house, the temple, when during the process they are surprised to find a book of the law in the debris. This triggers the most impressive revival in the history of Judah, by my account. But it required not only for Josiah to hear what was wrong, he further inquired of The Lord what to do. When those two parts were in place, he put an end to all of the pagan practices, borrowed from the many nation around them through the ages. It was genuine revival in him, and in some of the nation, but it was short lived. Imagine how bad things must be when "God's People" are surprised to find His words in His house. Sadly, such things plague the modern church in many of the same way, for the same reasons.
It is instructive to us to remember the big picture items in the history. Hearing God's direction as it was recorded. Having the right reaction and seeking God's forgiveness and direction. Then being obedient to His direction and removing the wicked things from around him.
A great model for the believer through the ages, if ever there was one.