Over the period of X - early XIV c., the German Empire had the rights of superiority over the Piasts' Poland, which involved tributes and loyalty oaths by its rulers. The origin of those rights has so far been chiefly sought in the Empire' s power and their periodical appearance and reality was supposed to reflect the then balance of powers. At the beginning, during Mieszko I reign, those rights pertained to certain part of Poland, but then they were supposed to apply to the whole of the country. ; This author has, for a dozen or so years, been trying to bring down the extent of Poland's dependency on Germany to a regional level. The reason is Germany's reign over Pomerania and Silesia, territories brought under the permanent political influence of the Carolings' stare whose eastern successor since the X c. was the German Reich. ; This paper looks at and assesses source documents from the period of IX-XII c. which seemingly attest to the tributary dependence of the whole of Poland, but in fact it got involved in a kind of dependence through its rule over Silesia, after wrenching it off from the Czech Kingdom, tributary of Germany, in late X c. ; In XIV c. Silesia went back under the Czech crown, Germany approving. Thus, in order to make the argument stronger, the introductory part of this paper (Part l) presents shortly those document sources which confirm Germany's rights of superiority over Silesia in XIII-XIV c. and the Piasts' consent to enter a vassal relationship with German and Czech rulers- and so become the dukes of the Reich, just as it also happened after the rebirth of the Polish Kingdom by the Kujawian lineage of the Piasts' relatives (Władysław Łokietek, Kazimierz Wielki). ; The Silesian Piasts, being the descendants of king Bolesław Krzywousty's first-born son, had the hereditary right to become Polish monarchs. Silesia could remain part of the Polish crown if only they had become the Polish kings, for it was only them - and which Henryk Probus attempted in late XIII c.- who could negotiate with the German and Czech rulers the unification of tributary Silesia with sovereign Polish Kingdom.