After the death of his parents, he gave away everything to the poor and began his theological studies. In due time, he was ordained priest by Msgr. Lampert, Bishop of Krakow, whom he succeeded in 1072. He visited his parishes every year, bringing about a spiritual renewal among the clergy and the laity. His house was always crowded with the poor, and he kept a list of widows and miserable people to whom he systematically distributed alms.
Poland at that time was ruled by King Boleslaus II, who had kidnapped a married woman to satisfy his lustful desires. After St. Stanislaus rebuked him for his adultery, the king became enraged and cut short the interview with threats. In front of such stubbornness, the bishop had no choice but to issue a sentence of excommunication.
When the king entered the cathedral of Krakow, he found that the services were at once suspended by the order of the bishop. Furious with rage, he pursued the saint to the little chapel of St. Michael outside the city and killed him while celebrating Mass. The guards then cut the body into pieces and scattered them to be devoured by wild beasts. St. Stanislaus died in 1097, and his relics were placed in the cathedral of Krakow.