Hedwig of Sagan (Polish: Jadwiga żagańska; before 1350 – 27 March 1390) was Queen of Poland as the fourth wife of Casimir III.
Casimir's lack of male heir spelled the end of the Piast dynasty in the Kingdom of Poland.
Hedwig was the third of five children born to Henry V of Iron and his wife Anna, daughter of Duke Wenceslaus of Płock.
Casimir needed a son and he chose Hedwig as it would to strengthen his ties with Charles IV, Holy Roman Emperor.
However, Casimir was committing bigamy as was still legally married to his second wife (it is unknown whether Christina was still alive at the time).