Boym sends numerous Indipetae, letters entreating General of the Jesuit order, Mutio Vitelleschi, to allow him to go to Asia on a mission. He benefits from the support of Marcin Hińcza, his superior and Jesuit Provincial in Poland in the years 1633 – 1636, who at Kraków Academy of the Society of Jesus holds in parallel the title of Rector.
November 27, 1641
Michał receives the Society of Jesus General`s approval to leave for China. He responds with a letter of gratitude.
March 30, 1643
He receives Pope Urban VIII`s blessing and in Lisbon with ten other priests and clerics boards on a ship living for Macau.
Sailing around the East and West coast of Africa, the ship stops at Madera and Green Cape Islands, Cape of Good Hope. The ship calls at the port in Mozambique, since 1609 (and up to 1975!) a Portuguese colony, where Boym spends winter. Among others, he participates in a hunt for hippopotamus, which he describes as "sea horses". He describes this hunt experience along with other descriptions of nature and customs of the aboriginal people in an essay entitled "Cafraria" (from the "Cafres" as the Arabs called the Bantu tribes.) He subsequently sends this essay to his Polish friend, Priest Ciślak.
In the spring, he continues his voyage via the Maldives to India. The ship finally anchors at the port in Goa, a city known as the Rome of the East, located on the center-west coast of the country. Since 1510 it remains in the hands of the Portuguese.
End of 1644
He reaches Macau, where he is sent to lecture and study Chinese at St. Paul`s College.
He is transferred to Ding`An county on Hainan Island. He begins his first research on the local fauna and flora and Chinese medical practices. There he begins working on his Atlas of China, "Magni Cathay", and gathers materials for his future opus on puls diagnosis known as "Clavis Medica ad Chinarum Doctrinam de Pulsibus" and for his groundbreaking book "Flora Sinensis".
November 1, 1647
Michał Boym, along with a few other Jesuits, is forced to perform an instant evacuation from Hainan Island after it`s occupied by Manchurians. They sneak out on a small boat.
December 24, 1647
Michał Boym and his companions arrive in Tonkin, an ancient kingdom roughly corresponding to Northern Vietnam.
Boym remains at the service of the Tonkin mission. Meantime he travels to Chang`an in Siganfu (presently the city of Xi`an in Shaanxi Province), one of the ancient capitals of China, where he makes a copy of the famous Siganfu Stone. This relic, otherwise called the Nestorian Stele, describes the story of the Nestorians, the first Christians in China, dating to the Tang dynasty (currently at the Beilin Museum in Xi`an.)
Most of China remains under continuous warfare between the ethnic Han dynasty, the Ming, favorable to the Jesuits, and the Qing established by the Manchus invading from the North. While Michał Boym is traveling to Chang`An and back, the Ming armies lose to the Qing and retreat. Returning to Tonkin, the missionary has to choose another, a much longer route through provinces of Sichuan and Yunnan.
End of 1649
Boym returns from Tonkin to Macau, where he takes a sermon. Father Alvar de Semedo (1585–1658), the deputy provincial in China, sends him to Zhaoqing in Guandong to the Ming Emperor Yongli, the last ruler of the so-called Southern Ming dynasty. He is there to assist a fellow Jesuit, Father Andreas Koffler (1603–1651). In the meantime, Koffler succeeds in converting to Catholicism the Emperor`s closest family, including his natural mother, official mother (the Empress), the emperor`s wife, his oldest son, Constantin, and many most important court officials.