The answer is: 40 years

1 Ki 2:11

King David's reign is one of the most captivating stories in the Bible, filled with drama, faith, and lessons on human vulnerability. It lasted for 40 years—a period often seen as a time of fulfillment in the biblical narrative, symbolizing a generation. David’s reign encompassed both the unification of Israel and the establishment of Jerusalem as its capital. This was crucial, as Jerusalem became the spiritual center for decades to come.

Interesting trivia: David wasn't born into royalty. He started as a humble shepherd, showcasing how anyone can rise to prominence through courage and integrity, exemplified in his famous encounter with Goliath. Remarkably, David's story has resonances throughout history; he’s made countless appearances not only in the religious communities but also in cultural art, literature, and music—even Shakespeare noticed him!

David is a complex figure; while he is celebrated as a man after God’s own heart (as noted in 1 Samuel 13:14), he is also acknowledged for his significant failings related to morality and leadership. His life reminds us that greatness is often accompanied by challenges and mistakes.

The echoes of David’s reign can be seen throughout biblical history, especially in terms of leadership and covenant. King Solomon, his son, succeeded him and continued the story, but the complexities of David's legacy challenged the nation of Israel in their understanding of repentance and the possibility of redemption. David truly lived an inspiring, if tumultuous, life!