After completing the Jesuit usual spiritual and intellectual formation, Ruggieri volunteered for the Asian missions and left for Lisbon, where he was ordained in March 1578 while waiting for a ship to take him to Goa.
Arriving in India (September 1578), he promptly started to study the language used on the Malabar coast and in 6 months reached such proficiency that he could hear confession.
In the process, and aware that several would be following him, he set up Shengma'erding Jingyuan ("St Martin House"), the first school for teaching Chinese to foreigners.
[2] Visiting villages in the region he baptized several families that formed the nucleus of further Christian communities in mainland China.
Ruggieri was accused by Cai Yilong (w Ts‘ai I-lung) of adultery with the wife of Lo Hung in October 1587.
But nothing became of it, the frequent death of Roman Pontiffs, and the deterioration of his own health, preceded the weary Jesuit's retirement to Salerno, where he died in 1607 without ever going to China again.