Founded by the very energetic vicar of Warminster, the Rev. James Erasmus Philipps, whose family were interested in missionary work. The original intention was to train boys and young men, who had little previous education but were capable of becoming good workers. Later on the aim was to train them for entry into missionary colleges, both at home and abroad. The Mission House was formally opened on October 5th 1860 with 10-12 students in a house near the church. By 1871 the range of education offered had grown considerably and the name was changed to St. Boniface College. In the same year the students built a corrugated iron chapel, which was enlarged by students in 1909 and was used until 1936. In 1890 the students built themselves a cricket pavilion and had a printing press, on which they were publishing a college magazine in 1896.
In 1897 the foundation stone of new permenant buildings was laid on the site of the old Wilton House, on the town side of the parish church. The first block of buildings was opened on August 1st 1899 and they were completed by 1901. They are built of Doulting stone, with Bath stone dressings, in the Jacobean style. The student numbers grew; in 1908 there were 40 and this later rose to 53. In 1913, after the death of the Rev. Philipps, the constitution of the College was changed and one of the purposes now listed was for the actual training of missionaries. The College closed during the First World War but then re-opened and flourished and in 1936 a new chapel and lecture rooms were built. The College closed for the Second World War and when it re-opened in 1948 it was in association with King's College, London, as a post-graduate training centre for missionary work. The numbers expanded to 57 students and a staff of three priest. In 1969 this fourth year course was moved from Warminster to Canterbury and the College closed. The St. Boniface Trust was set up and leased the buildings and land to Warminster School.