Historia narodu polskiego
Mostly written in the years 1776–1779 during the era of Polish Enlightenment and published in the subsequent decades, this ambitious project, inspired by the works of Voltaire, was unfinished, as Naruszewicz only completed the volumes covering the times up to the end of the Piast dynasty in the 14th century.
In 1775, Michał Wielhorski, one of Poniatowski's opponents, had published the treatise On returning the former government according to the original Republican laws (O przywróceniu dawnego rządu według pierwiastkowych Rzeczypospolitej ustaw), which relied on historical evidence to attack the king’s policies.
[1]: 25 In his "Memorial regarding the writing of a national history" (Memoriał względem pisania historii narodowej) penned in 1775, Naruszewicz outlined the project, stressing the novel importance of relying on archival materials, as well as on the need to collect and organize them.
While he had a number of assistants, including the King himself, Naruszewicz was the sole author, having given himself the goal of writing at least 500 words a day and dedicating much of his daily routine (from 8:30 a.m to 3:00 p.m) to this project.
[1]: 25 He would complain of the lack of materials for the latter periods, but also, would become increasingly involved in the politics of the Commonwealth, including the works of the Great Sejm that begun later that decade.
[1]: 25 His work follows a strict chronological layout, with chapters corresponding reigns, and subchapters, to years (beginning with 962), although a number of topics such as the monetary system, the Jews, or steam baths received lengthy footnotes.
[1]: 24, 27 [4]: 95–96 He criticized serfdom, but did not call for any major reforms, believing that mistreatment of the citizens reflects weak monarchy, and that the cure lies in strengthening the royal power and curbing the excesses of the nobility.
[1]: 27 Despite being a Roman Catholic bishop, in most matters he also sided with the king instead of Papacy, and following the Enlightenment's secularist trend, he refused to explain history as the outcome of divine mandate or intervention.
