Deditio (ritual)

Deditio or deditiones was a ritual of submission in medieval Europe. It was a ceremony of subjection between a monarch and his subject, and included the latter bowing or laying by the feet of the monarch, barefooted and wearing ropes. It was a planned ceremony, agreed upon, and was used as a means of avoidance of escalation of conflicts, a strategy of peaceful solving of conflicts.

...
Wikipedia