Born in 1878 to the German-born Martin Tritschler and Rosa Córdova, he was raised mostly by his uncle, who sent him to study at the Colegio Pio-Latino-Americano Pontificio and Pontifical Gregorian University in Rome.

[3] His father came from an old family of German farmers, whose roots date back to the earliest settlements in the Black Forest, and who were feudal servants of the monasteries of Friedenweiler, Reichenau Island, and Saint Gall.

[3] His father was forced to leave the farm due to primogeniture laws, and he moved to Mexico where he became a prosperous clock manufacturer and retailer.

The youngest of eight children, Tritschler's brother Martín, the oldest of the eight, entered the priesthood and in 1900 was consecrated Bishop of the Diocese of Yucatán, was elevated to archbishop in 1907, serving until his death in 1942.

His sixth oldest sibling, Alfonso, graduated from the Pontifical Gregorian University in Rome but decided not to become a priest, and pursued a career in architecture.

Tritschler's mother died when he was three, and his father was elderly, so he sent a young Guillermo to be educated by his maternal uncle Prisciliano Córdova, a prominent cleric of the Diocese of Puebla de los Ángeles.

Because he was sent to the college at the unusually young age of 10, a December 1932 catalog of past students records him as the pupil longest lived studying in Rome, at 14 years, two months, and 27 days.

[1][2][3] He celebrated his first Mass two days later on 21 June 1904, the Feast of St. Aloysius Gonzaga, in the Church of Nuestra Señora de Ocotlán, near the city of Tlaxcala.

The architect, Manuel Gorozpe, aware of Tritschler's esteem, asked his advice of the project, and was influenced to change some of the plans of the seminary.

Tritschler was the Chair of the Philosophy Department starting in 1911, and at the end of that year was also assigned to teach courses in Dogmatic Theology.

In 1916 he received the official appointment of "spiritual father," a position that entailed encouraging seminarians to pursue their vocation and complete their studies until ordination to the priesthood.

"The Holy See ignored Tritschler's excuses, and L'Osservatore Romano published his appointment as the sixth Archbishop of San Luis Potosí on 30 January 1931.

He always had a deep involvement with the seminary, visiting it on the first Friday of every month to celebrate Mass dedicated to the Sacred Heart of Jesus, and often coming by to hold discussions and lectures with the seminarians.