An analysis of the relationship between Jan III Sobieski and the people he distinguished shows that there were many mutual benefits. Social promotion was more difficult if the candidate for the office did not come from a senatorial family34. It can be assumed that, especially in the case of Atanazy Walenty Miączyński, the economic activity in the Sobieski family was conducive to career development. However, the function of the plenipotentiary was not a necessary condition for this. Not all the people distinguished by Jan III Sobieski achieved the same. More important offices were entrusted primarily to Marek Matczyński. Stanisław Zygmunt Druszkiewicz’s career was definitely less brilliant. Druszkiewicz joined the group of senators thanks to Jan III, and Matczyński and Szczuka received ministerial offices only during the reign of Sobieski. Jan III certainly counted on the ability to manage a team of people acquired by his comrades-in-arms in the course of his military service. However, their other advantage was also important - good orientation in political matters and exerting an appropriate influence on the nobility. The economic basis of the magnate’s power is an issue that requires more extensive research. This issue was primarily of interest to historians dealing with latifundia in the 18th century. This was mainly due to the source material. Latifundial documentation was kept much more regularly in the 18th century than before and is well-organized. The economic activity of the magnate was related not only to the internal organization of landed estates. It cannot be separated from the military, because the goal of the magnate’s life was politics and, very often, also war. Despite its autonomy, the latifundium wasn’t isolated. Despite the existence of the decentralization process of the state, the magnate families remained in contact with the weakening center of the state and influenced changes in its social structure. The actual strength of the magnate family was determined not only by the area of land goods, but above all by their profitability, which depended on several factors: geographic location and natural conditions, the current situation on the economic market, and the management method adopted by the magnate. In the 17th century, crisis phenomena, visible in demography, agricultural and crafts production, money and trade, intensified. In these realities, attempts by Jan III Sobieski to reconstruct the lands destroyed by the war and to introduce military rigor in the management center did not bring the expected results. Sobieski, however, introduced “new people” to the group of senators, who implemented his policy at the sejmiks and the Parliament, participated in military expeditions and managed his property.