G. A. Henty 
In the Reign of Terror 

Harry Sandwith, a sixteen-year-old English boy, is sent to live in France with the Marquis de St. Caux, a friend of a French nobleman Harry’s father once served.

The marquis is impressed with the English system of schooling and believes that his two sons, Ernest and Jules, will benefit from the influence and friendship of an independent and manly English boy.