They were originally a monastery of Trappist monks founded in 1882 by Pfanner, but were later branched off as a separate congregation by decree of the Holy See.

In 1882, Pfanner, then prior of Mariastern Abbey, founded a Trappist monastery in Mariannhill at the invitation of Bishop Charles-Constant Jolivet, OMI, Apostolic Vicar of Natal (later Durban).

[5] It engaged in missionary work, establishing a number of mission stations where priests and brothers taught the native Zulu people to read and trained them in trades and skills such as farming.

Following his report, the Sacred Congregation of Propaganda directed Bishop William Miller, OMI, the apostolic vicar of Transvaal, to facilitate the independence of the Mariannhill monks.

[2][6] After their separation from the Trappists, the Mariannhillers continued to work in South Africa, but also established presences in Germany, Switzerland, Austria, the United States, England, Canada and Spain.

[10] On 10 March 2019, George Kageche Mukua, a priest of the congregation, died as one of the passengers on board Ethiopian Airlines Flight 302.