Why It Happened

In medieval society, marriage was primarily a legal and economic contract rather than purely a religious or romantic union. Consummation was considered the final, binding element that made a marriage legally valid and irreversible. Witnesses—often family members, friends, or even servants—would be present in or near the bedchamber to verify that consummation had taken place. This was especially important for high-status marriages where significant property, titles, or alliances were at stake, as it prevented disputes about whether the marriage was truly valid.

How It Worked

The couple would be escorted to the bedchamber by wedding guests in a ceremony called "bedding." Witnesses might remain in the room during at least the initial stages, or they would wait outside for confirmation from the couple or servants. In some cases, bloodstained sheets were displayed as proof of the bride's virginity, which was considered crucial for establishing legitimacy and social standing.

Variations by Region and Class

The practice was more formalized and documented among the nobility and royal families, where the stakes were highest. Among common people, the custom likely varied by region and social circumstances, though the general principle that consummation was necessary to validate a marriage was widespread.

(http://www.autoadmit.com/thread.php?thread_id=5887469&forum_id=2#50032548)