How were law and order maintained in medieval europe?

Feudalism, a system to maintain power to rule, it was also a good way to serve local justice to local people which included peasants, carpenters, blacksmiths, weavers, bakers, and merchants and dealers. Under the feudal system, kings offered power to barons to control large pieces of land in their kingdom. Thus, the right to jurisdiction. Hope this helped. :)

The answer is athens and sparta.