Various cultures celebrated marriages in their own way, usually through some form of agreement between the families. That was after Man became "civilized" and stopped kidnapping his bride from the neighbors.

Prior to the Middle Ages, it was often enough that the bride and groom agreed to become betrothed, and that a third party witnessed it. This also made good sense too, particularly in rural regions that seldom saw a priest and had no churches.

But as civilization progressed, so did the need for a little more attention to detail. In Medieval times it wasn't uncommon for the families to draw up an agreement first, with regard to the dowry and other details, for which neither bride nor groom was present, and often not even consulted. There was then the official engagement, which might also be lacking either party, depending on whether there was a great distance involved. And occasionally, even marriage by proxy, when haste was required to bring another family into the fold for political or other purposes.

Only as European civilization approached the Middle Ages, did a priest become a regular part of the ceremony, and eventually the ceremony was contracted at the local church, but not inside it. Originally, marriages were performed on the steps, where the priest gave the bride to the groom, then everyone proceeded inside for a mass.