This book is a religious-historical biography of a Catholic priest named Henry Young, who played a crucial role in the development of the Catholic Church in Dublin, Ireland, in the 19th century. This work traces Henry Young's life journey, from his vocation to the priesthood, through his pastoral ministry, to his contributions to building and revitalizing the religious life of Catholics in Dublin. He is portrayed as a highly dedicated figure in public service, particularly during a time when the Catholic Church was still facing various social pressures and the lingering restrictions of the penal law era in Ireland. This book also provides a broad overview of the conditions of the Catholic Church in Dublin in the 19th century, the lives of Catholics after the penal law era, and the development of parishes, churches, and religious practices within the city. In his narrative, Henry Young is even dubbed a kind of 'apostle of Dublin' for his dedication to strengthening the faith of the people and building a more vibrant Catholic community. Overall, this book not only presents the life story of a priest but also serves as a historical document of the Catholic Church in Dublin, demonstrating how a religious figure contributed to the revival of faith amidst social and political change.