[1] Janssoone was born in the town of Ghyvelde, in the French Department of Nord, the country's most northwestern corner, on 19 November 1838.

He was the eighth and youngest of the thirteen children[clarification needed] of Pierre-Antoine Janssoone and Marie-Isabelle Bollengier, and was christened Frédéric-Cornil.

Four years later, in response, to a religious calling, the young Frédéric enrolled in a college and then graduated to the Institut Notre-Dame des Dunes in nearby Dunkirk to prepare for the priesthood.

After their completion, on 24 June 1864, he entered the novitiate of the Friars Minor, where he added the patronage of St. Yves to his name, making his profession the following year.

[1] In 1876 Janssoone applied to serve in the Order's international Custody of the Holy Land, which has been responsible for the Christian sites there and the pilgrims who visited them since the days of their founder, Saint Francis of Assisi.

[1] In addition to his many administrative duties during that period, Janssoone also served as a guide for the many Christian pilgrims who visited the Holy Lands from around the world.

Shortly after the start of his visit, however, he stumbled slightly, through giving a talk on liberalism, unaware that this topic was causing a major division between the politicians and the ultramontane Catholic clergy of the province.

Nevertheless, to quiet continuing complaints resulting from the infamous speech by the foreign visitor, that following March, the Archbishop of Quebec, Elzéar-Alexandre Taschereau, ordered Janssoone to leave the Archdiocese.

Taschereau tempered his action, though, with a command that collections for the Custody of the Holy Land were to be taken up in all churches of the ecclesiastical province on every Good Friday.

They saw him as reviving a tradition of the Franciscan missions to that nation which had started at the foundation of New France and had ended with the death of the last Recollect friar (a reform branch of the Order) there in 1813.

[2] Repeated requests to the authorities of the Minorite Order finally resulted in his assignment to serve the Custody in Canada on a permanent basis.

[1] Shortly after his arrival, Janssoone was drawn into the promotion of the local Marian shrine of Notre-Dame-du-Cap by Louis-François Richer Laflèche, the Bishop of Trois-Rivières, who wanted revive the sanctuary built there by the pastor of that town.

[1] While occupied with this, at the request of his superiors Janssoone also started to undertake massive fundraising drives which required travel throughout the province, a task he performed for fifteen years.

He would preach in churches and go house-to-house for this, braving the harshness of the Canadian winter and farm dogs, selling some of the many books he wrote at night instead of sleeping.

[1] In further service to the Franciscan movement, from his first arrival in Canada Janssoone worked to revive the Third Order of St. Francis, which had been established by the Recollect friars in 1681 for the spiritual growth of the laity, but had dwindled since the incorporation of the colony into Great Britain.

Theologians approved his writings on 14 February 1937, and his cause was officially opened on 26 June 1940, granting him the title of Servant of God.