Numbers, origins, average age and similar data on the composition of the Order's membership tell us a great deal about its way of life, its popularity and the relationship between the model of spirituality it offered and the needs and ideals of successive eras. In these matters it is difficult to go beyond speculation without concrete data. In this article the author has presented the results of her research based on a file of Benedictine nuns of the so-called Chełmno Congregation. This file includes female Benedictine monasteries in Poland that were either newly founded at the turn of the sixteenth and seventeenth centuries, or founded by nuns of the Congregation of Chełmno or one of its foundations, or formed after their foundation.