Rings have been worn since the Sumerian kingdom of Ur in 2500BC who viewed the circle as a symbol of eternity. These important signifiers were passed onto the Ancient Greeks, the Romans and then into Middle Age Europe. In the process, they took on new meanings of prestige, luxury and femininity. The Romans started the tradition of wedding rings but made theirs exclusively with gold. It was only after World War I that diamond wedding rings became so customary.