[2] Wanting to do missionary work, he joined the La Société des Missions Etrangères (MEP) with the intention of going to Vietnam.
[2] In 1827, after arriving in Asia, he was instead assigned to the Apostolic Vicariate of Siam where the existing bishop, Esprit-Marie-Joseph Florens had only one missionary priest.
[2] Bruguière taught at the school at the Church of the Assumption for several years and then after repeated requests by Florens for a replacement,[2] he was appointed by Pope Leo XII on February 5, 1828, the Coadjutor Vicar Apostolic of Siam and Titular Bishop of Capsus.
[2] An influx of funding and MEP missionaries into the region lessened the need for him to remain in Siam and it was proposed that he go to Korea and establish a new mission.
[2] Maubant would later be joined by Jacques-Honoré Chastan and Laurent Joseph Marius Imbert where they would eventually be arrested and martyred.