How did oaths and compurgators serve as evidence in early legal systems?

In early legal systems, particularly within Germanic tribal traditions, oaths and compurgators functioned as a primary method of settling factual disputes, a process known as compurgation or "wager of law."12

Rather than testifying about the specific facts of a case, a party would attempt to exonerate themselves by swearing a formal oath regarding their innocence or the truth of their claim. Because a lone oath was rarely considered sufficient evidence, the party was required to assemble a group of compurgators—typically 12 individuals—who would swear to the uprightness of the party they supported.13

These compurgators acted as character witnesses rather than fact witnesses; they did not need personal knowledge of the events in question and were essentially "drawn in" to perform a legal act of guarantee. The practice relied on the religious and social weight of the oath, as participants feared divine retribution for perjury. While this system provided a way to resolve disputes and maintain tribal peace, it lacked the rational analysis of evidence found in later legal traditions and was eventually supplanted by more complex procedures.3142