Note:  Do not rely on this information. It is very old.

Blood Covenant

Blood Covenant, a covenant cemented by blood, in very many cases by the sacrifice of a victim. One of its most widely known forms is the rite of blood-brotherhood, mentioned by Herodotus (iv. 70), in which two persons actually mix their blood as a sign of lasting peace or friendship, and this rite is supposed to constitute real relationship between them. Accounts of such a ceremony are frequent in narratives of African exploration.