The answer is: 40 years

1 Ki 2:11

King David's reign indeed lasted for 40 years, a number rich with biblical significance. He initially ruled over Judah for seven years before becoming king of all Israel for the remaining 33 years. This formation of a united kingdom marked a pivotal moment in Israel’s history. It’s interesting to note that the number 40 pops up frequently in the Bible. Think of the Israelites wandering for 40 years in the desert or Moses spending 40 days on Mount Sinai. It often symbolizes a period of testing or preparation!

David, known as a shepherd, warrior, poet, and unifier, was pivotal in solidifying the tribes of Israel into a strong nation. His reign not only brought military successes but also spiritual and cultural development. He was the composer of many Psalms, poetic hymns expressing everything from deep despair to ecstatic joy. And let’s not forget the famous story of his encounter with Goliath—it embodies themes of courage and faith that resonate through ages.

Interestingly, though David is often remembered for his strength and leadership, his life wasn't without conflict and consequences, particularly later on with the events surrounding Bathsheba. These narratives provide profound lessons on human nature, leadership, and divine justice, all intertwined with the fabric of Israel's story. David remains a complex character whose legacy not only shaped his time but continues to inspire millions today.