In 1924 Dom Anselm Lightbound took over the headmastership, which he retained until 1938. It was to him that fell the task of starting the larger secular school when, in 1926, it was finally decided to abandon the alumnate.
On March 8th of that year the plan was first tentatively approved. A part of the community did not welcome the abandonment of what had been a chief attraction to them of the life at Belmont, the absence of a school. However, at the Conventual Chapter of July 13th a majority voted in favour of a school open to all, and so the matter was settled. The consent of the Archbishop of Cardiff was readily given, but one major obstacle remained. The intention of the Founder had been quite clear, as had always been recognised by the Community, that Belmont was never to have a school for boys intended for the lay professions. It was clear that nothing could be done without obtaining the consent of Major John Wegg-Prosser who had been recognised, since 1902, as co-founder of Belmont with his father.


After a long discussion with Abbot Kindersley, Major Wegg-Prosser fell in with the new ideas, though his permission for the school was only for ten years and he stipulated that there must not be more than fifty boys. A few years later he increased the number to seventy and then in 1936 to one hundred, without any time restriction.

The new school opened in September 1926. It began with only eleven pupils, all of whom had been in the old alumnate. There were no real school buildings so the boys continued to be accommodated in the old parish school with one dormitory and one study room in the monastery. However Fr. Anselm had vision and courage and he was already looking far ahead. For the next twelve years he nursed the struggling school and brought it from infancy to, if not manhood, at least adolescence. He found it with practically no equipment or premises, no traditions and little spirit. When he left it in 1938 the numbers had more than trebled, the buildings, though still inadequate, had much increased, and his successor was able to say that it had been handed over to him with all the essentials of a public school.


The process of expansion began immediately. Before the end of 1926 a temporary school building was begun in the open space between the refectory and the then library. By the end of 1927 there stood on that site an asbestos hall, seventy feet long by thirty feet wide. With the opening of this study hall, which could be divided by curtains into classrooms, the old village school was abandoned.
Attention had also to be given to the provision of playing fields. Hitherto the alumnate, and sometimes the monks, played association football in a triangular field lying in the fork between the Abergavenny and Hay roads, as the fields immediately adjoining the monastery sloped upwards. But now Fr. Anselm, with some stout-hearted helpers, set to work to level part of them. They toiled with pick, shovel and wheelbarrow, off and on, for ten years. They produced a central field of two and a half acres, which proved to be level to within an inch when professionally surveyed ten years later.

It was clear that if the school was really to expand to anything like the desired numbers there would have to be considerable development of new buildings. No one could see where the money for this was to come from, and the slender capital of the monastery was already strained to the utmost. The boys had very poor quarters compared with provision at other schools and parents could hardly be favourably impressed. However, for the moment the erection of new buildings was out of the question and the best that could be done was to encroach on the monastery itself.

By 1931 it was possible to set about building some new permanent rooms. On April 29th plans were approved for an extension of the refectory wing. This would give dormitories above and playrooms below, as well as a masking wall between the two new extensions and the library, which would conceal the temporary hall of 1927. Building began on June 10th and on St. Michael's Day the foundation stone was laid in the east wall by Abbot Kindersley with full ceremonial. The structure was built around a steel frame filled with brick, with exterior sand-covered bricks. The building was completed in time for the opening of the term in September 1932. The total cost was just under £7,000.
At the time of the opening of the new buildings the school was dedicated to Blessed John Kemble, the Herefordshire martyr, and at that time the numbers in the school had risen from eleven to forty. The financial depression which hit the whole country during the early 1930’s checked its growth for a year or two, and although by 1937 there were over fifty boys, the number had fallen again to thirty-seven in the following year. In 1938, Fr. Anselm's health broke down and he relinquished charge of the school.