To mark the day, a love story between a geometric shape and the organ we know as the heart, spanning centuries and traversing medieval battlefield, cathedral, gambling hall and bedroom. Author Iain Gately details the long and meandering path the figure ♥ or cardioid, and the organ that pumps blood, took before they were united in current culture as the icon of love we call "heart." The ♥ symbol has been attributed to regeneration as a Classic Greek image of vine leaves, Viking tributes to Odin signaling battle madness, a sign of courtly love in medieval times, sacred love of Christ for the church, and low connotations of various body parts. As for the organ, its biological function was mysterious until the 17th century, and throughout history the physical seat of love has wandered to other organs, notably including the liver.