The Preparatory School of RBAI was founded at ‘Inchmarlo’ Marlborough Park Belfast in 1917. This was as the result of the boarding houses at Inst being closed and the Governors deciding to buy a property at 106 Marlborough Pk North. The house was originally built and owned by a prosperous linen merchant who it is believed took his holidays at the Inchmarlo estate on Deeside.
The first Headmaster was John Seymour, himself an old boy of Inst and he built Inchmarlo into a happy and successful preparatory school. He presided over the move in 1935 from Marlborough Pk to the bigger premises at Stirling House in Cranmore Park. It was so named after its generous donor Mr JH Stirling who had been a Chairman of the Board of Governors.
Due to popular demand the name Inchmarlo moved with the school and the original building was renamed ‘The Red House’ of Richmond Lodge.
It was in 1947 that Mr Seymour retired thus marking the end of an era in the history of Inchmarlo, the Boarding element having closed with the move in 1935.
Under its subsequent four Headmasters, Edgar Lockett (1947 – 1970), Brian McMahon (1970 – 1992), Alan Armstrong (1992 - 2015) and Mr Andy Smyth (2015 - ) the school has grown in size and reputation while still retaining that very special family atmosphere.