St. Thomas the Apostle of India kindled the light of faith during the first century A.D. in the Southern Part of India. The early Franciscan Missionaries later continued the Gospel preached by him in Kanara in the year 1510. Befittingly Mangalore is called “Rome of the East”. Alphonso-de-Albuquerque a Portuguese explorer conquered Goa and was its Viceroy of the Indies from 1510-1515. This made it easy to Portuguese King Immanuel to send missionaries to Kanara for evangelization of Christianity. Albuquerque conquered this territory from the Bijapur Sultan Ismael Adil Shah. Later in the year 1542 St. Francis Xavier a Spanish Jesuit arrived in Goa from Portugal and propagated the true faith.

The Portuguese under Diego de Silveira attacked Mangalore in the year 1568. On January 5th 1568 the city was occupied and Portuguese built a fort called the “Fort of St. Sebastian” at the place where now stands the Deputy Commissioner’s office. The Portuguese also had trade links in Kanara and Malabar and as such they built a factory for curing, storage of spices and other condiments prior to shipment. Since they felt the necessity of a church for their spiritual welfare they built a church (Holy Rosary Church) referred to as the “Factory Church” of Bolar. The Royal stone emblem of the Portuguese king is lying at the entrance of the Cathedral as insignia of their landing in 1568. The Cathedral now stands in the same place where the Portuguese built their first church after capturing Mangalore on 5th January 1568. They opened three churches namely 1) Holy Rosary at Bolar 2) Our Lady of Mercy at Ullal 3) St. Francis Assisi at Farangipet. In the year 1570 Fr. Vincent who was at the time the Provincial of Jesuits in Goa sent a fresh batch of missionaries into Kanara. The Archbishop of Goa exercised his ecclesiastic jurisdiction over the coast. On December 3rd 1609 Pope Paul V extended his jurisdiction along the coast as far as Dharmattam. The Italian traveler Pietro Della Valle visited Mangalore in 1623 and he mentioned about the existence of these 3 churches mentioned above. The Holy See appointed Thomas De Castro a native of Divar in Goa Vicar Apostolic of Kanara on 30th August 1675. He later died on 16th July 1684. The venerable Fr. Joseph Vas played an important role in the history of the Rosario Church in the year 1681. Archbishop Brandao of Goa assigned him this task. Venerable Fr. Joseph Vas repaired the existing Bolar Rosario Church, which was known as the “Factory Church”.

In the year 1910 Rev. Fr. H.I. Busoni S.J. the then Parish Priest demolished the old structure and commenced the work on the large and beautiful church worthy of dignity of a Cathedral. Br. Divo S.J. (St. Xavier’s) Bombay Mission was the master architect. Bishop Perini was consecrated here on 4th December 1910 when the sanctuary alone had been completed. This dome is a crowning work of architectural magnificence in the diocese. Fr. Busoni erected a belfry and installed 4 sonorous bells from Italy. Bishop Perini S.J. then Administrative Apostolic of the Diocese consecrated the main altar of the Cathedral on 3rd April 1924. He died in Bangalore on 28th June 1932 and interned at Calicut Cathedral on 30th June 1932.

The period from 1784 to 1799 forms a turbulent and sad page in the history of the Christians in Kanara. On 30th January 1784 the British surrendered to Tippu Sultan’s forces. Tippu Sultan was enraged with the Christian community as he suspected their fidelity, as his subjects and issued orders to his Commanders to arrest all Christians in Kanara, confiscate their lands and valuables and destroy their churches and lead them as captives to Srirangapatnam. This catastrophe took place on the fateful night of Ash Wednesday February 21st 1784. These cruel orders were carried out and several thousands of Christians in his domain were lead as captives to Srirangapatnam. Their fate was sad and gloomy and many perished through starvation and fatigue on the way. The survivors who reached Srirangapatnam were rounded up and by torture forced to embrace Islam.

During this period Tippu’s forces desecrated and destroyed 26 out of the 27 churches in Kanara and Rosario Church was one of them. Thus began their long suffering and bitter lent for 15 years to follow. Srirangapatnam was besieged and fell to the British forces in 1799 commanded by Colonel Arthur Wellesley, the future Duke of Wellington, who was destined to defeat Napoleon Bonaparte at the battle of Waterloo. Colonel Arthur Wellesley was the brother of The English Governor-General of India, Richard Wellesley, Second Earl of Morning ton. Thus ended the torture and captivity of Christians.