733,000 km²), with a population of over four to five million people (about a third of its population of 14 million before the partitions). The treaty was a major success for Frederick II of Prussia: Prussia's share might have been the smallest, but it was also significantly developed and strategically important. Russia received the largest, but economically least-important area, in the northeast. Notable supporters of the partition, in addition to Poniński, included Michał Hieronim Radziwiłł and the bishops Andrzej Młodziejowski, Ignacy Jakub Massalski, and Primate of Poland Antoni Kazimierz Ostrowski, who occupied high positions in the Senate of Poland. The senators who protested were threatened by the Russians (represented by Ambassador Otto von Stackelberg), who declared that in the face of refusal the whole capital of Warsaw would be destroyed. Other threats included executions, confiscation of estates, and increase of territory subjected to partition. Some senators were arrested and exiled to Siberia. Other legislation The partitioning powers (in particular, Russia) demanded that the Sejm pass further reforms, with the intent of strengthening their power over the Commonwealth. The original commission was allowed to work till January 1774, extending the Sejm, which was adjourned again. The commission was unable to carry out its changes in that period, and thus it was allowed to extend its deliberations once more; there were ultimately seven such extensions. The Cardinal Laws, a quasi-constitution endorsing most of the conservative laws responsible for the inefficient functioning of the Commonwealth, were confirmed and guaranteed by the partitioning powers. The Sejm also continued enacting laws reducing religious tolerance in the Commonwealth. The passive electoral rights of the Orthodox, Eastern Catholics and Protestants were diminished, with a restriction limiting the number of non-Roman Catholic Sejm deputies to three (one from Greater Poland, one from Lesser Poland, and one from the Grand Duchy of Lithuania). They were also banned from election to the Senate or ministerial positions. Royal power was restricted, as the king lost the power to give titles and positions of military officers, ministers and senators, and the starostwo territories for Crown lands, most of which would be awarded through an auction. In return, the king received four starostwa for personal possession. The royal (free) election was confirmed, with stipulations that future kings had to come from the Polish nobility, and sons and grandsons of any king could not succeed him to the throne till two others had held