Pope Pius XII canonises Dominic Savio, who was 14 years old at the time of his death, as a saint, making him at the time the youngest unmartyred saint in the Roman Catholic Church. In 2017, Francisco and Jacinta Marto, aged ten and nine at the time of their deaths, are declared as saints.

Pope Pius XII was the head of the Catholic Church and sovereign of the Vatican City State from 2 March 1939 until his death on 9 October 1958. He is the most recent pope to take the pontifical name "Pius".

Canonization is the declaration of a deceased person as an officially recognized saint, specifically, the official act of a Christian communion declaring a person worthy of public veneration and entering their name in the canon catalogue of saints, or authorized list of that communion's recognized saints.

Dominic Savio was a 19th-century Italian teenager who was a student of John Bosco and became a Catholic saint. He was studying to be a priest when he became ill and died at the age of 14, possibly from pleurisy. He was noted for his piety and devotion to the Catholic faith, and was canonized a saint by Pope Pius XII in 1954.

A martyr is someone who suffers persecution and death for advocating, renouncing, or refusing to renounce or advocate, a religious belief or other cause as demanded by an external party. In colloquial usage, the term can also refer to any person who suffers a significant consequence in protest or support of a cause.

The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.27 to 1.41 billion baptized Catholics worldwide as of 2025. It is among the world's oldest and largest international institutions and has played a prominent role in the history and development of Western civilization. The Church consists of 24 sui iuris (autonomous) churches, including the Latin Church and 23 Eastern Catholic Churches, which comprise almost 3,500 dioceses and eparchies around the world, each overseen by one or more bishops. The pope, who is the bishop of Rome, is the chief pastor of the church.