Cacella was born in Aviz, Portugal, in 1585, joined the Jesuits at the age of nineteen, and sailed for India in 1614 where he worked for some years in Kerala.
In 1626, Father Cacella and Father João Cabral, another younger Jesuit priest, travelled from Cochin to Bengal where they spent six months preparing for a journey through Bhutan, which would eventually take them to Tibet where they founded a mission in the town Shigatse (near the River Brahmaputra), the residence of the Panchen Lama and of the great Tibetan monastery of Tashilhunpo.
Also it was Cacella who, for the first time, described to European civilization a fictional place called Shambala (a Sanskrit term indicating "peace/tranquility/happiness").
According to Tibetan Buddhism this is an ideal country located north or west of the Himalaya Mountains): during the 20th century the myth inspired James Hilton to write his novel Lost Horizon, with its Shangri-La.
From Cacella's own words : "We asked as many questions as we could about the kingdom of Cathay [China] but have heard nothing of it by this name, which is completely unknown here; however, there is a kingdom which is very famous here and which they say is very large called Xembala [Sham-bha-la] next to another called Sopo [Sog-po] (Mongolia); the King does not know the law of Xembala and he has asked us about it many times.