It is an icy, end-of-term day when I visit The Oratory School on the Berkshire/Oxfordshire border. A tug-of-war match boys on one side, masters on the other, the long stop being the substantial figure of the chef is taking place, punishing the grass of the games pitch. Red-cheeked boys stand around in harlequin-patterned games kits, cheering lustily when their team lets go of the rope early and the masters collapse on to the ground. ‘Come on, the Common Room,’ shouts an upright, tweed-cap-wearing man on the sidelines: Clive Dytor MC, head master, one of a pair of labradors at heel (‘one black, one yellow: the school colours’). The scene suggests that this is a typical boys’ boarding school, with a healthy emphasis as The Oratory indeed has on games. They are played every day. ‘Boys are like dogs,’ observes Mr Dytor. ‘They need to be exercised daily, fed regularly and watched at all times.’

However, there are ways in which The Oratory is not typical. For one thing, it is a proudly Roman Catholic institution, although only half the pupils are Catholic. This year will be a doubly important one, as the school will not only celebrate its 150th anniversary, but also the beatification of its founder, Cardinal John Henry Newman. Newman, who founded the Birmingham Oratory in 1848, wanted to set up a Catholic school on public-school lines.

The old Catholic families, who had remained true to the faith through the years of penalty and exclusion, had sent their sons to be educated at religious establishments in France and Belgium; Downside and Ampleforth were home versions of this sort of school. After Catholic Emancipation in 1829, however, the Catholic Church received an influx of converts from the Oxford Movement: confident, professional men who had themselves been to public school and wanted a similar education for their own boys ‘Eton, minus its wickedness,’ as Sir John Simeon said. They turned to Newman as the most prominent convert of the age, and he was closely involved in The Oratory for its first 30 years.

In the 1860s, Newman’s example persuaded the Oratory Fathers in London to open a similar school there. Both were originally fee paying, although the London Oratory, famous for having been chosen by the Blairs, became a selective school in the State system, and also now takes girls in the sixth form. The Oratory, still a public school, continues to be restricted to boys. It acquired Woodcote House, its present building, in 1942.

The Oratory is the smallest boys’ boarding school. Eton boasts 1,300 pupils and Winchester 750, but The Oratory has only 420. Size is one of the determinants of its character. As we walk along corridors and through courts, Mr Dytor, now in his MA’s gown, has a word for every boy he meets, congratulating one on his exam success, another on his rowing even encountering one of a pair of identical twins doesn’t throw him. The Oratory breathes cosiness. It is an atmosphere in which the personalities of individual children are noticed and developed, and the 54 members of the academic staff ensure this happens. ‘From here,’ muses the long-serving ancient history master, Ronnie Womersley, ‘you could imagine you were in the middle of the Black Forest.’ You aren’t; the pimple on the horizon is Reading. Good train services make it easy for London parents. The latter like the relatively unpressured atmosphere, although the universities to which pupils go on are good: three Oxbridge places this academic year.

The school looks for marks above 55% at Common Entrance. Yet selection doesn’t stop there. Over lunch in the head master’s study, with its leather chairs and log fire, Mr Dytor tells me: ‘Parents come here and I say to them: “You’re looking at me, but I’m also looking at you.”’ If he doesn’t feel that the mores of the family will suit the school, the boy doesn’t come. Over-pushiness, on the part of parents, is not welcomed. The result, based on an intake of well-adjusted boys, is a happy school. It is not, at a time of credit crunch, every head master who could risk it. But not every head master is Mr Dytor.

Since then, the Catholic ethos has been brought to the fore. These days, schools such as The Oratory don’t seek to exclude boys of other faiths, but to soft-pedal on their own teaching, which, in Mr Dytor’s view, can cause them to lose focus. ‘Being Catholic is a fundamental part of our special character, and why parents choose us over other schools.’ In recent decades, Catholic families haven’t sought to maintain their sense of separation from the rest of society, happy for their children to be assimilated into the mainstream at conventional public schools. ‘My battle is to get them out,’ declares Mr Dytor, with a smile. He admits it’s something of a crusade.

Not surprisingly, given Mr Dytor’s background, The Oratory’s combined cadet force is top notch. Among the sports at the school is real tennis, a game that, according to pro-fessional Mark Eadle, ‘appeals to everyone, not only to the top sports players. With its arcane rules and strangely configured court, it can be a mind sport, like chess’. Real tennis courts being a rarity (when it went up in 1989, it was the first to have been built in the UK for 80 years), The Oratory hosted the world championships in 2006. Above the door from the sports centre, with its 80ft heated pool, hangs a shield celebrating the gold medals won by Oratorians at the Athens Olympics the Athens Olympics, 1896, as it happens, although old boys have recently gone on to play rugby for England and cricket for county sides. A case of trophies in the hall demonstrates the school’s target-shooting success.

The tug-of-war match has finished. There are three cheers for each team. Lots of noise, lots of mud. The memory I take away is of the chapel, made out of an old barn, a spiritual place of whitewashed walls, oak-tie beams and tranquility. ‘It is almost a Classical country-house Catholic chapel, with early-morning services in English and Latin,’ says Mr Dytor. ‘The motto Newman chose translates as heart speaking to heart. It’s what we’re about.’