Question

When and why was the finger known as "the ring finger" called that?

Answer 1

Because that’s where you put the ring on

Answer 2

Before medical science discovered how the circulatory system functioned, people believed that a vein ran directly from the fourth finger on the left hand to the heart. Because of the hand–heart connection, they chose the descriptive name vena amoris, Latin for the vein of love, for this particular vein.