The economically and politically advancing burger class was becoming increasingly important in the cultural life of the Commonwealth, beginning with the German culture-inspired intellectual activity at Danzig and Thorn around the middle of the 18th century, and culminating with wealthy Warsaw townspeople of the final years of the Republic, who built urban palaces and patronized cultural endeavors. The scientist and writer Stanisław Staszic, a leading figure in the Polish Enlightenment, was the most prominent of the non-noble intellectuals of the period. The urban intelligentsia, crucial in the dissemination of the Enlightenment ideology, originated both from impoverished "szlachta" and from urban families; some of the strongest supporters of the national reform movement and leaders of the Kościuszko Uprising's left wing originated from that group. Many burgher sons attended leading educational institutions in the Commonwealth and abroad. Radical ideas and currents were readily assimilated by the politically very active elements of Warsaw's lower classes. Members of this group massively supported reformist postulates of the Great Sejm, promoted the French Revolution ideals, helped distribute political literature, and were the faction that matured and became indispensable during the Insurrection.