22 June 1958, when the new school at Lampang was blessed, marked the beginning of a new era in the expansion of the Province of Thailand. At the time it numbered seven houses: Assumption College in Bangkok (1901), St Gabriel’s in Bangkok (1920), Montfort College at Chiengmai (1932), Assumption Commercial College in Bangkok (1939), Assumption College at Sriracha (1944). St. Louis at Petriu (1948) and the juniorate at Sriracha (1948). A few years later the number of establishments was more than twice what it was then.

From 1958 to 1967 five more schools were started. The one at Lampang (1958) in the north of the country owes its origin to the reputation of Montfort College, 100 km away. The school at Thonburi was built in 1961 in Bangkok on a piece of land donated by a past pupil of Assumption College. A similar donation was made in 1963 by the governor of Rayong who wanted to establish in his home town a school as good as the one at Sriracha, 140 km away.The school at Ubon was already in existence and was run by the mission when the Brothers took it over after years of talks. The same year the mission at Khorat offered to give them a piece of land on which to build a new school; it was opened in 1967.                                                         /