William was born in Cork, Ireland, in 1608. He entered the Order when he was 18 years old and did his studies at Valladolid, Paris and Brussels. Following ordination to the priesthood he returned to Ireland as a member of the Augustinian community in Cork, a city which became predominantly Protestant with the war of 1641. Following the arrival of Cromwell in Ireland in August, 1649, and the outlawing of priests throughout the country, William was forced to exercise his ministry in secret. He was betrayed while about to celebrate the Easter Vigil on Holy Saturday, 1654, and was taken to the prison at Clonmel. His crime: being a priest in Ireland! He was offered his freedom if he would renounce his Catholic faith, but he refused. Accused of treason, the court, under pressure of the military, declared him guilty. He was led to the gallows dressed in his Augustinian habit and, from the place of execution, pardoned those who had betrayed him. He asked absolution if there should be a priest in the crowd, thinking that a fellow Augustinian, Fr. Dennis O'Driscoll, the former provincial whose secretary William had been, was present. The day was May 12, 1654. His body was interred at the Augustinian Abbey in Fethard. William was beatified by John Paul II on September 27, 1992 together with sixteen other Irish martyrs.
The tragedy of a Church divided is played out in the lives of people such as Blessed William who suffered for their fidelity to promises made and a faith inspired by heroic love. Love of God and love of neighbor, recommended to us as the first principle of the Rule, is ultimately the final explanation for the courage and steadfastness of Blessed William and others like him.