Joseph Kowalski was born in Siedliska near Rzeszów, Poland, on 13 March 1911 to Wojciech and Zofia Borowiec, the seventh of nine children. His parents, practising Catholics, were farmers who owned a modest farm.
After primary school, they enrolled him in the Salesian College at Oswiecim (Auschwitz). Joseph immediately distinguished himself for his commitment to study and service, and his sincere cheerfulness. He joined the Immaculate Concpetion Sodality and the Missionary Association, later becoming its president.
He literally fell in love with the Salesian charism and its Founder, whose example he followed in everything: commitment to joyful animation of religious and civil holidays, apostolic presence among his companions and, in particular, the primacy of spiritual life.
As a young student he began to write his diary, which passes on to us his devotion to Mary Help of Christians and to the Eucharist: "Oh my Mother," he wrote "I must be holy because this is my destiny. O Jesus, to you I offer my poor heart ... . Grant that I may never depart from You and that until death I remain faithful: I would rather die than offend you, even with a small sin. I must be a holy Salesian, as was my father Don Bosco. .
He made his temporary profession in 1928 in Czerwinsk and received his priestly ordination on 29 May 1938 in Krakow. He was appointed provincial secretary. He looked after a youth choir in the parish and looked after the most difficult young people.
In 1939 Poland was occupied, but the Salesians continued their educational work. This is the main reason for the dramatic arrest on 23 May 1941: the Gestapo captured Fr Kowalski along with eleven other Salesians working in Krakow. Initially he was interned in the Montelupich prison in the same city; from there he was transferred to the Auschwitz concentration camp on 26 June, receiving the number 17,350. In the concentration camp he devoted himself secretly to the apostolate: he heard confessions, celebrated mass, recited the rosary, held hidden lectures, including on Don Bosco, reinforcing the desire in his prison companions to fight for survival.
Suffering, harassment and humiliation. Discovered with the rosary, he refused to step on it, thus speeding up his martyrdom, which happened at Auschwitz on 4 July 1942. His body was first thrown into the excrement container, then burned in the camp crematorium.
His fellow villagers began to venerate his memory, believing that his sacrifice had fertilised Polish vocations. Pope John Paul II was also of the same opinion, and took a personal interest in the cause of several Polish martyrs. Finally, he beatified them in Warsaw on 13 June 1999.
The decree of martyrdom was published on 26 March 1999; he was beatified on 13 June 1999 by John Paul II.