Summary
In this article an effort is made to explain how texts in sources from medieval Frisia containing wergeld amounts or wergeld-related amounts can be dated roughly.
Wergeld was the payment primarily for slaying a man to be made by the perpetrator and his kin to restore peace with the heirs and the kin of the victim. In his research for the evolution of the standard money in Frisia the author found by chance that the wergeld amounts had a constant silverequivalence over centuries although the amounts itself were varying primarily caused by the varying silverequivalence of the money unit of account in the course of time. Hence wergeld was deeply rooted in a nation's tradition.
This implies that from a given wergeld amount the silver equivalence of its unit of account can be derived and by knowing the date of that silverquivalence the date of the wergeld itself can be determined. Although the silverequivalence of the main ingredient of wergeld - to be called the 'normal wergeld' - was constant, its appearance in the sources was very varied because of aggravating or relieving circumstances that might increase or decrease the final amount. Hence defining a wergeld date requires investigation in these circumstances. Only a rough impression how this can be done could be given below.