I was watching CSI (crime scene investigation) with my wife last night. The crime scene was at a wedding and a remark was made to the effect that the"historic" purpose of bridesmaids was to ward off evil spirits. Google turned up this comment amongst others...
CHOOSING YOUR BRIDESMAIDS
A BRIEF HISTORY
The history of the bridesmaid varies across cultures, religions and time periods. In early Roman times, bridesmaids formed a kind of bridal infantry as they accompanied the bride to the groom's village. This "protective shield" of similarly outfitted bridesmaids was supposed to intervene if any wayward thugs or vengeful suitors tried to hurt the bride or steal her dowry.
However, the Western bridesmaid tradition seems to have originated from later Roman law, which required ten witnesses at a wedding in order to outsmart evil spirits believed to attend marriage ceremonies. The bridesmaids and ushers dressed in identical clothing to the bride and groom, so that the evil spirits wouldn't know who was getting married. Even as late as 19th century England, the belief that ill-wishers could administer curses and taint the wedding still existed. In Victorian wedding photographs, for example, it can take quite a bit of inspection to pick out the bride and groom from among the other members of the bridal party!
I commented to my wife to the effect "well there goes having bridesmaids at a witness wedding" but she refused to rise to the bait. I do find it incredible that they are so anal about such things as having toasts or throwing rice but would let this blow right by them. They are a religion (cult) of pick and choose. Maybe there will be new light on this soon. Maybe someone should send in a "questions from readers"™