For modern brides, identical bridesmaid dresses may be somewhat dated. However, in Roman times, matching outfits meant good luck and were a common wedding tradition. The Romans believed that evil spirits would attend the wedding in an attempt to place a curse on the bride and groom. To confuse the evil spirits, bridesmaids acted as decoys and dressed identically to the bride. The purpose was to confuse the evil spirits causing them to be unsure which one was the bride.  This would result in the evil spirits not disturbing the bride and allowing the couple to wed.