File:Wojciech Gerson - Zjawa Barbary Radziwiłłówny.jpg

Summary
According to the legend, in 1569 the king Sigismund Augustus, who was in mourning after death of his beloved wife Barbara Radziwiłł, asked the renowned sorcerer Master Twardowski to evoke her ghost. The experiment was successful with support of a magic mirror, which today is kept in the Węgrów Cathedral.