EN
(Polish title: Dlugosc zycia zakonnic w swietle zródel sredniowiecznych i nowozytnych. Ograniczenia, mozliwosci i propozycje badawcze). The recently developed Polish prosopography of religious orders has not paid much attention to the issue of the length of nuns' life, both biological and chronological (the number of years spent in enclosure), in contrast to the issues of the social and geographical background or the size of monastic communities. A medievalist is limited in this respect by the scarcity of sources and their documentary character. In Poland there are no mediaeval predecessors of modern books of profession, called Libri vitae, which have survived in Western Europe and Britain. Furthermore, nunneries, not only in Poland, are known for scarcity of chronicles and necrologies, which are an invaluable source of data about mediaeval male congregations. The basic sources of data on mediaeval nuns and monks are normative documents, i.e. the rules and constitutions. Deeds usually mention the narrow ruling elite, and hence over-represent abbesses, prioresses and their deputies, and their counterparts in male congregations. The normative sources contain few clues as to the age of candidates and the longevity of monks and nuns. Due to the regulations introduced by the Council of Trent, and the increasing level of literacy, monastic documents from the modern era are more copious and of better quality. New types of documents produced by nuns and monks, as well as the new regulations contained in the Trent decrees, allow us to undertake a thorough analysis of prosopographic issues, including the length of biological and chronological life. The principal sources are books of profession, which noted the biographical data of novices, and books of the dead, in which data were recorded regularly and according to new rules. Books of the dead are particularly valuable since they often incorporated information from mediaeval necrologies and other earlier sources which have not survived until today. The Trent regulations required systematic and neat records, therefore books of profession are the richest and the most reliable source of prosopographic information. Data from books of profession indicate that nuns lived much longer than lay women in the given epoch. Many nuns lived to be fifty, which was considered an old age in the early modern period. Such longevity was primarily due to the fact that nuns did not bear children, childbearing being the basic cause of high mortality rate among women. Research on the length of the biological and chronological life of nuns before the end of the 16th c. is hampered by the character of the sources. The length of life can only be determined in the case of some nuns, mostly abbesses and prioresses. The fragmentary and shaky data from documents, rarely supplemented with information from necrologies, do not provide grounds for generalizations. On the basis of individual examples we can only pose tentative hypotheses and speculate about possible tendencies. The end of the 16th c. is marked with a new category of sources, including books of profession, which are most valuable for prosopographic research. They allow us to undertake complex research on whole congregations in periods ranging up to several hundred years. Ample narrative sources help to verify data from books of profession, which greatly enhanced the reliability and credibility of the results. The available data allow us to trace changes in nuns' longevity, and to conduct comparative analyses on a scale that is unavailable for previous centuries.