Hahn was born in Berlin in 1886. He had studied at Oxford, read Plato's Republic as a young man, and conceived an idea of education that combined classical philosophy with hard physical challenge. With Prince Max of Baden he founded Salem in 1919, on the principle that the First World War had been caused partly by a generation educated to think but not to act. Hahn's school built character through expedition, seamanship, and service. By the early thirties, Salem was famous across Europe - and Hahn was a marked man. After his release he was sheltered in Britain and offered the lease on the Gordon family's old estate at Gordonstoun. He moved in on 14 March 1934. Two boys enrolled in the first term. By the start of the Second World War there were 135.

Among the early transfers from Salem - sent on by Hahn himself when the school in Germany became impossible for Jewish staff and progressive students - was a young Greek prince called Philip, nephew of the king of Greece, who was effectively stateless after his family fled the Greek revolution of 1922. Philip thrived at Gordonstoun. He sailed, he climbed, he led. He played hockey on a pitch so rough that players spent half-time clearing pebbles. Hahn personally set up the team, and Philip later joked that he hoped one day they might be among the best Scottish girls' teams. He was made Guardian - head boy. Philip married the future Queen Elizabeth II in 1947. Two decades later he sent his eldest son to the same school.

Charles, Prince of Wales, did not love Gordonstoun. The young prince, shy and bookish, was bullied by classmates who knew exactly who he was and resented him for it. He famously - and bitterly - called the school 'Colditz in kilts', after the German prisoner-of-war castle. He later described his years there as a prison sentence. The Netflix series The Crown dramatised the unhappiness, to the reported irritation of the Queen. Yet Charles became Guardian like his father before him, and the school's patron when he came to the throne. Princes Andrew and Edward followed in their turn. Princess Anne, who could not attend in the era when it was still boys-only, sent both of her children. Today Charles III is King and the patron of the Old Gordonstounians.

Hahn's ideas travelled further than Moray. The Moray Badge scheme he founded in 1936 - physical challenges leading to a final project - became the model for the Duke of Edinburgh's Award, now active in over 140 countries. His approach to character through outdoor challenge gave rise to Outward Bound, founded with shipowner Lawrence Holt during the Second World War to toughen young merchant seamen against the Atlantic. In the United States it became EL Education, an English and arts curriculum used across the country. Gordonstoun's alumni list runs from royalty through actors (Jason Connery, Oona Chaplin) and musicians (Duncan Jones, son of David Bowie; Adrian Utley of Portishead) to Olympic rower Heather Stanning. The school still requires expeditions in the Cairngorms and seamanship aboard its 80-foot ketch Ocean Spirit.

Hahn's experimental school has also had to reckon with darker realities. In 2017 Gordonstoun was named among the institutions investigated by the Scottish Child Abuse Inquiry chaired by Lady Smith. The school confirmed eleven cases of abuse by staff and 82 claims of bullying between pupils, mostly from the 1970s and 1980s. In 2018 a former teacher, Andrew Keir, was convicted of indecently assaulting thirteen-year-old pupils between 1988 and 1991 and jailed for twelve months. The school issued a sincere and unreserved apology. Lady Smith's June 2024 finding was unambiguous: 'children were abused at Gordonstoun and Aberlour in a variety of ways over a long period of time.' Hahn's school continues - some 500 boarders and 100 day pupils between five and eighteen - the highest-profile boarding school in Scotland, still bound to its founder's vision and still working through its own history.