Who took down Sparta?

Can you shed some light on the mysterious event that brought down the once powerful city-state of Sparta? What factors contributed to its downfall? Was it internal strife, the rise of other military powers, or a combination of both? Were there any significant battles or campaigns that played a pivotal role in Sparta's decline? Furthermore, how did this historical event impact the balance of power in the ancient Greek world and shape the political landscape of the region?