The answer is: 31 years

2 Kings 22:1

Josiah, one of the most fascinating kings of Judah, took the throne at a mere eight years old! His reign, lasting a solid 31 years, is often noted for significant religious reform and devotion to the worship of Yahweh. With his eyes set on renewing the covenant and restoring the temple, his story unfolds primarily in 2 Kings 22-23, depicting sweeping changes in Judah under his rule.

Instead of following in the footsteps of compromised predecessors, Josiah sought to follow what he remembered of authentic worship—not just as political maneuvering, but as a heartfelt command. Interestingly, during his reign, the Book of the Law was discovered in the temple, prompting an epic revival among the people. This rediscovery of scripture seemed almost "forgotten," echoing the timeless need for individuals and communities to reflect on their guiding principles.

Around 640-609 BCE, when Josiah ruled, Judah faced mighty political pressures—the mighty Assyrian empire loomed large during this period, and Josiah’s reforms can be seen as an act of sovereignty and desperation to forge identity amid chaos. His dedication is often contrasted with a general trend of idol worship on the rise, putting pressure on true believers.

Josiah’s story reminds us that a revival can blossom even in the bleakest circumstances, offering hope that heartfelt sincerity can spark transformation within entire communities.