Vena Amoris

Latin for "vein of love" is said to be the reason why we wear our engagement rings on the fourth finger (the ring finger) of our left hand.  The story/tale/myth dates this back to the Egyptians who believed this vein led directly from the heart to the ring finger on our left hand.   Whether this was an actual belief or not is debated, but whoever/whatever started this tradition was damn successful at getting it to stick around!