The history of Dromantine estate dates back to the middle ages. The ancient Irish clan of Magennis dominated most of South County Down from the 14th - 17th century and owned vast tracts of land in that area, including what is now Dromantine Estate. Following the political upheavals of the early 17th c. one of the Magennis clansmen, Murtagh, became the owner of an estate of 4200 acres within the precinct of Clanagan
In 1741 the Manor of Clanagan passed from Magennis ownership to that of a Scottish Family called Innes. In 1806 Arthur Innes built the original part of the existing house in Neo-classical style. When he died in 1820 he left a magnificent house within a beautifully landscaped demesne complete with a newly formed lake. His grandson, Arthur Charles Innes, became the owner of the property and in the 1860s extended the original house (now called Dromantine House) making it even more stately and imposing.
In the early 20th c. the fortunes of the Innes family waned and they decided to dispose of Dromantine.
At the same time the Society of African Missions (SMA) which was based in Cork was looking for a suitable property in which to prepare their students for missionary work in Africa. Under the guidance of Fr. Maurice Slattery the SMA bought Dromantine House and the 320 acre estate in 1926. It was their seminary until 1972 and during these years about 600 young men were ordained priests and went from Dromantine as missionaries to Africa.
Several extensions were added to accommodate the growing number of students. Paying special attention to a harmonious blend with the original architecture, work on St. Patrick's wing on the east side commenced in November 1931. St. Brendan's wing on the west side was built in 1935 and a new Chapel, which was added to the end of this wing, was consecrated by Bishop Mulhern on 18th May 1937. St. Colman's wing with 62 study-bedrooms for students and a new assembly / lecture hall were opened in 1959.
In 1996 the SMA decided to carry out major renovations and refurbishments in order to update the buildings and make them suitable for a modern Retreat and Conference Centre. When these were completed, a 21st century, comfortable and well equipped Retreat and Conference Centre was reopened in 2001.
In 2004 the original 19th century courtyard building was sensitively and completely renovated to provide additional conference rooms and facilities. The recently built "African Link" connects the main conference centre with the new facilities in the courtyard. It contains a display of beautiful African carvings and art which celebrate the skills of African artists from areas where the SMA work - highlighting the strong historical and present day links between Dromantine and Africa.