10. Jan (John) * 1339/1340 + after 18 May 1359
The son of Kazimierz and Eufemia of Mazovia. Following the example of his eldest brother, Bolesław, he chose to go into the Church, becoming a cleric in the Wrocław Diocese. He must have died young, there being no further mention of him after 1359.
(K. Jasiński, Rodowód, p. 145)
