Fóstbræðralög

Fóstbræðralög refers to a specific type of bond in Old Norse literature and society. The term literally translates to "foster-brotherhood" or "sworn brotherhood." It describes a deep, often formalized, relationship between two men who were not related by blood but became as close as brothers through a solemn oath or ritual.

This bond was not merely friendship but a pact of mutual loyalty, support, and defense. If one fóstbræðralag fell into danger, the other was obligated to come to his aid, even at great personal risk. This commitment could extend to avenging the other's death. The concept is prominent in many sagas and Eddic poems, illustrating its significance in the social and legal fabric of the Viking Age.

The ritualistic aspect of fóstbræðralag often involved symbolic acts, such as bleeding on each other or mixing blood in a shared vessel. This solidified their shared fate and unwavering commitment. The strength of this bond is frequently depicted as being as powerful, if not more so, than familial ties, shaping alliances, influencing feuds, and providing a crucial support system in a often harsh and unpredictable world. The concept highlights the importance of chosen kinship and loyalty in Norse culture.