The practice of blood feuding was a fundamental aspect of the Icelandic judicial system during the Middle Ages. A feud, something so complex that it lacks an agreed-upon definition, involved vengeance and hatred among groups - animosities that played themselves out through acts of aggression, compromise, or dishonor. In Iceland, blood feuds were not only part of the Viking justice system, but also social and political in nature. According to the Icelandic sagas and other historical sources, blood feuding involved specific guidelines and processes.