Santiago Piquer  (Facultad de Filología y Geografía e Historia, University of Basque Country, Spain)

" From Portugal to Lithuania. A comparative study of the adult mortality seasonality in the XVIth-XVIIIth centuries".

This paper intends to improve our knowledge of the similarities and differences in demographic behaviour among the european countries and regions in the past. It is focused on the study of adult mortality seasonality employing a comparative approach.

It is based in the rich documentation preserved about the XVIth-XVIIIth centuries members of the Society of Jesus. This religious order, famous for its strongly centralised and hierarchical structure, sistematically recorded all the aspects corcerning the evolution of its affiliates. So we have an available sample of nearly 68000 deaths in the period 1540 ( when the society was founded) - 1773 ( when it was dissolved for first time), including date and place for the major part of these defunctions. Taking account the life-style´s uniformity of the jesuits, this paper contends that the differences detected across Europe were probably linked to specific circumstances of the regions they lived, worked and died.
The geographical division of Europe used in this paper in based on the territorial distribution (Provinces) of the Society. The following list identifies the Jesuits´Provinces with the present geographical divisions their covered:

- The Province of Portugal. (Portugal)
- Castille, Aragon, Betica and Toledo Provinces. (Spain)
- France, Aquitaine, Champagne, Toulouse and Lyon Provinces. (France)
- Flando-Belgium and Gallo-Belgium Provinces. (Belgium)
- Upper Germany, Upper Rhine and Lower Rhine Provinces. (Germany and Switzerland).
- Western and Eastern Sicily, Neapolitan, Sardinia, Roman, Milan and Venice Provinces. (Italy)
- The Province of Austria. (Austria, Slovenia, Croatia, Romania and Hungary)
- The Province of Bohemia. (Czech Republic and Slovakia)
- The Province of Poland. (Poland)
- The Province of Lithuania. ( Poland,Lithuania and Belarus).

To sum up, we offer a paper that recording and maping the continuities and changes in the adults mortality seasonality wants to do a contribution to one of the main topics of today´s research: the existence or not of demographic frontiers inside Europe in the past. Finally the characteristics of the several seasonality patterns detected are also analised, together with their relationship with mortality levels and with the role played by the great mortality crises, specially with those caused by the Plague.