Why is it when you ask someone to marry you that you get down on one knee?
We presume this tradition grew out of the bent knee being a sign of submission and supplication. You’ll see this gesture often in some of the great works of art. One bends one’s knee when being received by royalty, as well as during spiritual communication with God in church, for example. The bent knee is the suitor’s demonstration to his bride-to-be of his submission, supplication, and loyalty.