十九世紀愛爾蘭出現有史以來第一位愛爾蘭籍的樞機主教--庫蘭（Cardinal Paul Cullen, 1803-1878）。庫蘭長期以來在梵蒂岡（Vatican）擔任神學院院長，建立了他與教廷高層人士良好的人際關係。1847年愛爾蘭發生大飢荒造成無數的傷亡，天主教在此期間負起撫慰人心的重要工作，愛爾蘭人一直期望教會，能與他們一起對抗英國當局的壓迫，卻因為天主教缺乏領導中心，派系繁多，且許多人對於英國殖民政府加諸在愛爾蘭的政策，有不同的解讀。庫蘭被派到愛爾蘭整頓天主教，以免被英國的新教蠶食，1849年先被任命為主教，1852至1866年則升任為都柏林教區的大主教。庫蘭在神職生涯中召開兩次宗教會議，確立了天主教發展的方向，也由於庫蘭對天主教的貢獻，教宗於1866冊封庫蘭為樞機主教。十九世紀愛爾蘭面對諸多因素，天主教的發展受到嚴重威脅，庫蘭成功地解除這些危機並帶領天主教派向新的發展方向。

In the nineteenth century, Paul Cullen was a very influential figure. Cullen served as a rector in Rome for twenty-nine years. He had good relationship with the clergy in Vatican. The Great Famine of 1847 created an opportunity for him to practice Catholicism in Ireland. He was appointed bishop of Armagh in 1849, and promoted as archbishop of Dublin in 1852. In 1866, Cullen became the first Cardinal in Irish history. Cullen was an extreme Ultramontanist, and vigorously opposed all secret societies in the country with revolutionary aims, as well as the system of mixed education then in force. He was a strict disciplinarian and worked hard to improve the morale and education of the clergy. He created the modern Irish Catholic Church and directed a new way for the development of Irish Church.