If we were to seek an exemplary model of a genuine regionalist then Jakub Chojnacki would be our ideal candidate. This native of Mazovia and a resident of Plock was actually neither born in Plock nor settled down there of his own choice; nonetheless, he devoted all his skills to the town, becoming a true local patriot. J. Chojnacki spent several score years in the Scientific Society of Plock, acting as its secretary, vice-chairman,chairman (for 34 years), and honorary chairman; in his capacity as the vice-president of Plock he made it possible for hundreds or even thousands of people to enjoy decent living conditions, was engaged in the current issues of the town, and showed concern for its development and the welfare of the residents. Moreover, J. Chojnacki inspired numerous scientific sessions and organized meetings, discussions and symposia not only on the most relevant problems of the town but also about wider-scale - Polish and European - questions. Perceived by his colleagues and those close to him as a symbol of the science and culture of the capital of Mazovia, a true embodiment of effective initiatives promoting the environment, the town and the region, dr. J. Chojnacki far exceeded traditional forms of activity. He attached particular importance to monuments of the past, especially those of Plock, and all sorts of historical souvenirs, devoting his tireless energy to obtaining them and sharing his enthusiasm with others. He managed to achieve an almost impossible feat - his consistent and outright obstinate efforts enabled the western portal of the local cathedral to feature a replica of the Plock Door, lost centuries ago, a monument reflecting the place of the town on the map of European twelfth-century culture. This indubitably greatest accomplishment among the multiple undertakings pursued by Jakub Chojnacki will be gratefully recalled both by Plock and the country as a whole. The distinctive personality of Jakub Chojnacki shall remain a part of the modern history of Plock and Mazovia; his energy, integrity and characteristic ability to combine the past and the present shall be missed by all.