The peculiar position occupied by the Jews in Poland made their social autonomy both necessary and possible. Constituting an historical nationality, with an inner life of its own, the Jews were segregated by the Government as a separate estate, an independent social body. Though forming an integral part of the urban population, the Jews were not officially included in any one of the general urban estates, whose affairs were administered by the magistracy or the trade-unions. Nor were they subjected to the jurisdiction of Christian law courts as far as their internal affairs were concerned. They formed an entirely independent class of citizens, and as such were in need of independent agencies of self-government and jurisdiction. The Jewish community constituted not only a national and cultural, but also a civil, entity. It formed a Jewish city within a Christian city, with its separate forms of life, its own religious, administrative, judicial, and charitable institutions. The Government of a country with sharply divided estates could not but legalize the autonomy of the Jewish Kahal, after having legalized the Magdeburg Law of the Christian urban estates, in which the Germans constituted the predominating element. As for the kings, in their capacity as the official "guardians" of the Jews, they were especially concerned in having the Kahals properly organized, since the regular payment of the Jewish taxes was thereby assured. Moreover, the Government found it more to its convenience to deal with a well-defined body of representatives than with the unorganized masses.