A Capuchin priest, Father J. J. P. O'Reily, who came to New Zealand in 1843, cared for the Roman Catholics of Wellington and built their first chapel. In 1844 Father Comte, S.M., was sent by Bishop Pompallier to take charge of the missionary work among the Maoris of the district.

Bishop Viard laid the foundation stone of St. Mary's Cathedral, Hill Street, in September 1850, just four months after his arrival in Wellington. Within two years he founded schools and a providence for Maori girls, this work being cared for first by Viard's own Congregation of Sisters, and from 1861 by Sisters of Mercy sent from Auckland. During the sixties people throughout the diocese, especially those on the goldfields of Otago and Westland, contributed generously for the enlargement and completion of the cathedral – first opened in 1851 and in its enlarged state dedicated in 1867. It was destroyed by fire in 1898 and the present Sacred Heart Basilica was erected on the former cathedral site in 1901.