Gatehouse school was founded by Phyllis Wallbank in May 1948, in the gatehouse of St Bartholomew the Great Priory Church, West Smithfield. A pioneer of educational development, Mrs Wallbank was also a friend and professional associate of Maria Montessori. She set out to create a school in which:
Children of any race, colour, creed, background and intellect shall be accepted as pupils and work side by side, without streaming or any kind of segregation, with the aim that each child shall get to know and love God, and to develop their own uniqueness of personality, to enable them to appreciate the world and the world to appreciate them.
The School moved to its present site in the mid-1970s, where Christian values and principles still form the backbone to school life. Gatehouse sets out to provide the best education possible for children, establishing a modern outlook on primary education while ensuring that it retains the key values on which it was first founded.