Geoffrey Trease has been writing history adventure stories over an incredible 63-year span. Apart from some Marxist views in his first few stories leading to lines such as “The capitalists will hang on to the last ditch!”, his winning formula has remained very similar.

A teenage hero or heroine of impeccable morals and unquestioned virginity sets out on a quest. Help is usually on hand from a largely benign environment marred only by the odd villain or two. After several dangerous episodes, virtue finally wins its own reward.

Such adventures are invariably set at times of great historical interest.Meticulously researched, they teach as well as entertain. In his latest work, Danger in the Wings, the background to the American War of Independence is linked to the British theatre in the age of Garrick and Sheridan.

Dan, a young American over here to learn acting, falls for his lovely stage colleague Jessica. A jealous rival steals letters Dan’s parents have sent him from Boston and then accuses him of being a spy. Dan just escapes with the aid of Jessica - and a couple of stage pistols - to return one day when he can. A note at the end confirms that, while the hero and heroine are imaginary, most of the other characters are based on real people including “Gentleman” William Smith, the old Etonian who would never act on Monday as it interfered with his fox hunting, and Henry BateDudley, the Fighting Parson and theatrical talent-spotter.

A more flamboyant writer such as Leon Garfield would have concentrated on character and atmosphere. Trease prefers to describe in detail how scenery was once hauled from town to town by huge “caterpillars” - special coaches long enough to carry the lengthy stage flats. There are other digressions, for example, on the history of Bath or highwaymen.

The writing is always clear if a little staid (a visit to Vauxhall Gardens and a brief, innocent encounter with a prostitute is still condemned on the next page as “somewhat unsavoury”). Words like “glee” and “zest” look back to a previous age of historical writing, but such is Trease’s professionalism that his story continues to carry readers along as before. No chapter is long enough to drag, and each ends on a note of interest or suspense.

This may be history with the more seamy side omitted, or very much played down. But with so much attention to harsh realism in contemporary teenage stories, there is a need for some quieter, less generally alarming imaginary journeys. The national curriculum’s emphasis on the importance of historical fact should also work in favour of this gentle master-craftsman, whose personal charm and devotion to studying the past shine forth.