Wikipedia
Ringen is the German language term for grappling ( wrestling). In the context of the German school of historical European martial arts during the Late Middle Ages and the German Renaissance, ringen refers to unarmed combat in general, including grappling techniques used as part of swordsmanship.
The German tradition has records of a number of master-Ringer of the 15th to 16th centuries specializing in unarmed combat, such as Ott Jud.
Medieval and early Renaissance wrestling treatises present both sport and combat techniques together as one art. The distinction is made more frequently by modern practitioners than is present in historical sources, but in a select few examples the terms for sportive grappling or geselliges ringen and earnest unarmed combat or kampfringen (where kampf is the Early Modern German term for " duel") were used to describe specific techniques which were only suitable for one scenario or the other.
There are no known sources describing medieval rulesets for Ringen competition. However, many living folk wrestling styles in Europe are fought until a throw is completed. The lack of detailed ground wrestling in the medieval wrestling treatises supports the theory that in both competition and combat the throw was more important than extended ground wrestling.
While sportive grappling had fixed rules that prohibited dangerous techniques, usually starting in grappling hold and ending with a throw or submission, kampfringen can be considered a system of unarmed self-defense including punches, joint-locks, elbow strikes, chokeholds, headbutts and (to a limited extent) kicks.
The German tradition of ringen was eclipsed during the 17th century as the modern Baroque understanding of nobility precluded the participation of the higher classes in wrestling matches. Wrestling continued to be practiced among the lower classes, giving rise to the various traditional styles of folk wrestling.