UCD founder Cardinal John Henry Newman has been canonised by Pope Francis, making him the first English saint of the modern era.
In front of tens of thousands of pilgrims in the Vatican's St Peter's Square, the pontiff elevated the theologian, priest and writer, who lived from 1801 to 1890, to sainthood.
Prince Charles, who represented the UK at the ceremony, praised the cardinal as a man of principle, highlighted his work championing Catholicism and paid tribute to his enlightened thoughts on faith, education and conscience.
Education Minister Joe McHugh represented the Irish Government.
Cardinal Newman shocked Victorian society when, as an Anglican priest, he converted to Catholicism, but he went on to help change attitudes towards the Catholic Church, raising its standing in British society.
He is famed for his intellect, but part of the new saint's enduring appeal is his "sweet humility", a description made by a woman whose miraculous healing from a life-threatening pregnancy complication has been attributed to Newman.
Melissa Villalobos recovered from a torn placenta in 2013, which threatened her unborn child's life and her own, after praying to the priest for help.
Four other religious figures were canonised yesterday.
They were Indian mystic and founder of a religious order Mother Mariam Thresia and Swiss laywoman Marguerite Bays, who dedicated her life to her community.
Also elevated to sainthood was Mother Giuseppina Vannini, a religious sister from Rome; and Brazilian-born Sister Dulce Lopes.
Lopes set-up a foundation which is now one of the largest charitable organisations in her homeland.
Francis called on all Christians to adopt Cardinal Newman's definition of someone of faith, something he described as being "kindly lights".
He told the crowds: "Today we give thanks to the Lord for our new saints. They walked by faith and now we invoke their intercession.
"Three of them were religious women; they show us that the consecrated life is a journey of love at the existential peripheries of the world.
"Saint Marguerite Bays, on the other hand, was a seamstress. She speaks to us of the power of simple prayer, enduring patience and silent self-giving.
"That is how the Lord made the splendour of the Easter radiate in her life.
"Such is the holiness of daily life, which Saint John Henry Newman described in these words, 'The Christian has a deep, silent, hidden peace, which the world sees not... The Christian is cheerful, easy, kind, gentle, courteous, candid, unassuming, has no pretence, with so little that is unusual or striking in his bearing, that he may easily be taken at first sight for an ordinary man'.
"Let us ask to be like that 'kindly lights' amid the encircling gloom."