The chapel built at the façade of the cathedral on the northern side of the main entrance was founded by the fourth and last wife of Władysław Jagiełło – Sophia of Halshany (died 1461). Almost thirty years later Kazimierz Jagiellon with his wife Elizabeth of Austria founded the twin Holy Cross Chapel on the other side of the entrance. The Chapel of the Holy Trinity featured richly painted decorations in the Byzantine-Ruthenian style, but unfortunately no trace of them has survived numerous remodelling projects. The stone sepulchral plaque of Queen Sophia has survived to this day but is significantly damaged. Originally it had bronze appliqué decorations.
We are all well aware that to enter this Cathedral can not be without emotion. More I say, you can not enter it without the internal tremor, without fear because it contains in it - as in almost no Cathedral of the world - the enormous size, which speaks to us in all our history, our entire past.cardinal Karol Wojtyla