Beja was the chief garrison town of the province and the principal theatre of the twenty-eight years' war with Spain that followed the Portuguese Revolution of 1640.

She made her religious profession as a Franciscan nun of the Poor Ladies at sixteen or earlier, without any real vocation, and lived a routine life in that somewhat relaxed house until her twenty-fifth year, when she purportedly met the young French nobleman Noël Bouton.

[1] During the years 1665-1667, the marquis of Chamilly spent much of his time in and about Beja, and probably became acquainted with the Alcoforado family through Sóror Mariana's brother, who was a soldier.

Custom permitted those in religious orders to receive and entertain visitors, and Chamilly found it easy to get round the trustful nun.

Before long their affair became known and caused a scandal, and to avoid the consequences Chamilly deserted Soror Mariana and returned to France.