Miche was forced to leave about a year later, when Ang Em, a rebelling prince of Cambodia, declared himself king of Battambang, and the town was all but emptied of its inhabitants.

He traveled up a tributary of the Ba River to the Central Highlands of Vietnam, hoping to convert the Montagnard people to the Catholic faith.

Duong's death in 1860 triggered a political crisis when his successor Norodom's brothers, Sisowath and Si Votha, rebelled.

Two years later, he was transferred to Fraize, where he remained until he entered the seminary of the Paris Foreign Missions Society (MEP) on 10 September 1835.

The course was a brief one, providing him with basic geographical knowledge about his approximate posting, but not the language, which he was supposed to learn during the six-month sea voyage.

Following tradition, Miche only learned the exact location of his mission, Cochinchina, during the sending off ceremony in the MEP chapel of the Rue du Bac.

In 1838, he finally moved into Cambodia, traveling with a fellow missionary, Pierre Duclos, to Paknam by boat and then through the jungle to Battambang on foot.

[1] Miche and Duclos' time in Battambang among a congregation of mostly Chinese merchants and mixed-race descendants of Portuguese was cut short just a year later.

[4] Minh Mạng, the Emperor of Vietnam, was opposed to the introduction of Christianity[5][4] and Vietnamese troops arrested the priests when they reached the first Montagnard villages.

In early 1849, Miche left for an excursion inland up the Mekong, but his boat was not fit for the conditions and he only reached Sambok in Cambodia.

[9] In 1854, Miche proposed a conference in Bangkok to concentrate evangelization efforts in Laos, but the political situation in the area was becoming tense and hampered his activities.

[5] Miche had drafted a letter requesting protectorate status for Duong to send to Emperor Napoleon III of France.

[5] His funeral three days later culminated in a procession of two hundred carriages to the tomb of Pierre Pigneau de Behaine, a famed French missionary, five kilometers outside of the city.

[1] Miche is recognized as an early European influence in the Indochina region and instrumental in the establishment of the French Protectorate of Cambodia.