Leonia Nastał (born Maria Nastał; 8 November 1903 – 10 January 1940) was a Polish Catholic nun from the Congregation of the Sisters Handmaids of the Blessed Virgin Mary Immaculate [pl], a mystic, religious writer, the Venerable of the Catholic Church, and advocate of the idea of mystical spiritual infancy.

Maria Nastał was born in Stara Wieś, a village near the town of Brzozów in the Dynowskie Foothills [pl] in the Outer Subcarpathia.

[7] Her mother, on the other hand, was balanced, cheerful, and very devout;[4] Maria learned about religiosity from her through shared prayers and reading religious books.

[16][17] Maria Nastał's mother, Katarzyna, seeing her younger daughter's abilities, did not want her to interrupt her education and sent her for private English lessons in Brzozów.

[16][17] When the front moved away from the family's area, and her father sent a written permission, Maria continued her education at the 6-grade Queen Jadwiga Public School in Brzozów from 1917 to 1919 and completed the fifth and sixth grades.

[16][11] In 1919, she applied to join the Congregation of the Sisters Handmaids of the Blessed Virgin Mary Immaculate but was not accepted due to her father's opposition.

[11][18] During her youth, the Jesuit priests leading the parish had a significant influence on her, especially Father Kutyba, who was her confessor and taught her about sacrificial love for Jesus Christ and striving for perfection.

[11][25][26] Her father Franciszek, who returned from America in 1921, vehemently opposed her desire to enter the convent, but due to his daughter's act with the nail, he stopped trying to change her decision, although he did not reconcile with it.

[9][25][18] On 8 November 1921, Maria Nastał left her family home and went to the Benedictine convent in Staniątki to study at the local teacher training college, but she did not feel comfortable there.

[28] Finally, Franciszek Nastał announced to his daughter that he did not want to see her in his house, and after 8 years of efforts, Maria entered the Congregation of the Sisters Handmaids of the Blessed Virgin Mary Immaculate [pl], a religious order founded by Father Edmund Bojanowski, on 31 December 1925.

[37] In July 1927, after completing her first canonical year of novitiate, she went to Vyzhniany [pl] near Lviv for a mission, where she was to become more acquainted with the works of the Congregation and the duties of her vocation, and also to discern whether she would be capable of receiving religious vows.

[38] After taking her vows, she remained in Stara Wieś and for 9 months studied English in preparation to go to the United States, where the Congregation had had missions since 1926, and work for the American-Polish community.

[11][40] In December 1932, she went to Stara Wieś and for several weeks gave history lectures to novices, and in January 1933, she went to Poznań, where she took care of sisters participating in a 6-week pedagogical course.

[41][11] On 13 April 1934, Sister Leonia made her perpetual profession to Mother General Eleonora Jankiewicz, in the presence of a chaplain and her parents.

[50] In December 1939, sensing her impending death, Sister Leonia, with the consent of the Mother Superior, moved from Szczawnica to Stara Wieś.

[53] On 9 January 1976, the Dicastery for the Causes of Saints announced the decree Nihil obstat, allowing the process to begin in the diocese,[13] which commenced on 8 December 1976.

[11] In late June and July 2006, the drafting of the document Positio concerning the Venerable Leonia Nastał was completed and submitted to the Secretariat of the Dicastery for the Causes of Saints in Rome.

While in Poznań, Leonia Nastał experienced mystical encounters in which Jesus Christ allegedly revealed to her the path to holiness based on humility and unlimited trust in God.

[58][59][60] It was characterized by humility, awareness of one's own weakness and inability to act without God's help, sincerity, simplicity, gentleness, sweetness, and innocence.

[44][58] She also mortified herself by enduring humiliations and quarrels from her father in silence, giving up minor pleasures, and refraining from eating favorite dishes.

[73] The nun's father, although initially categorically opposed to his daughter's vocation, embittered by her decision, did not participate in the ceremony of investiture and vows, but under her influence, he converted and began to attend Mass and receive communion daily.

[19] According to Cecylian Niezgoda of the Order of Friars Minor Conventual, Leonia Nastał made at least two mistakes in her mystical spiritual life.

[82][83] In her works, she taught love for one's neighbor, kindness, respect for the elderly and disabled, as well as patriotism and the search for God in nature and in other people.

[81] The third group of writings includes Notatki rekolekcyjne covering the years 1926–1934, conducted at the request of her confessor, Father Wojciech Trubak; Dziennik duchowny in eight consecutive notebooks covering the years 1934–1939; and Historia powołania, an autobiographical essay written shortly before her death at the request of Mother General Eleonora Jankiewicz.