The legal order of the old Polish Republic in the period from the 16th c. to the 18th c. was diversified, mainly in systemic terms. It corresponded, though the reasons for its creation varied, to the ethnic, cultural and religious diversity of the state. Defining the legal order of the old Polish Republic in the form of a specific systematics, based on various criteria of division of the then existing legal systems, while showing the existence of the order in the context of a certain hierarchy, reflects a certain specific case of operation of a legal order which, despite certain inconvenience, did not lead to extraordinary collisions however. Owing to this, our reflections have much more universal application to similar situations that exist in the contemporary world.