Merovingian law was not universal law equally applicable to all; it was applied to each man according to his origin: Ripuarian Franks were subject to their own Lex Ripuaria, codified at a late date, while the so-called Lex Salica (Salic Law) of the Salian clans, first tentatively codified in 511 was invoked under medieval exigencies as late as the Valois era. In this the Franks lagged behind the Burgundians and the Visigoths, that they had no universal Roman-based law. In Merovingian times, law remained in the rote memorisation of rachimburgs, who memorised all the precedents on which it was based, for Merovingian law did not admit of the concept of creating new law, only of maintaining tradition. Nor did its Germanic traditions offer any code of civil law required of urbanised society, such as Justinian I caused to be assembled and promulgated in the Byzantine Empire. The few surviving Merovingian edicts are almost entirely concerned with settling divisions of estates among heirs.
Source: Merovingian dynasty – Wikipedia