Belle's birth and baptism are recorded in the parish register of the church of Saint-Sulpice, Paris, and quoted in Eugène Piot's Le Cabinet de l'amateur for the years 1861 and 1862:[3] The 17th day of January 1674 was baptized Simon-Alexis, son of Jean Belle, master painter, and of Anne de Champs his wife, the godfather Simon-Alexis Sourdeval, son of Guillaume Sourdeval; the godmother Marie Mercier, daughter of Louis Mercier.

[Signed] Louis Sourdeval, Jean Belle.Belle studied first under his father, then continued his training in the studio of François de Troy (1645/46-1730), a painter at the court of King James II in exile at Saint-Germain-en-Laye.

[4] After war broke out again between Great Britain and France in 1702, their portraits of James Edward Stuart ('The Old Pretender') and his sister the Princess Royal continued to be smuggled across the Channel.

[1] Several copies exist of his portrait of James Edward Stuart in armour and standing beside the English Channel, on which there are warships, pointing towards the cliffs of Dover.

[1] Belle's most famous portrait of James Edward Stuart dates from 1712, just before he left Saint Germain for Lorraine, and shows him in a tent in a military outfit.

He painted Louis XV's one-time fiancée Mariana Victoria of Spain, whom he later did not marry; he worked also for Jacobites in France, and as late as 1724 signed a portrait of Marie-Charlotte Sobieska (James Edward Stuart's sister-in-law) pictor regis Britann (painter to the king of Britain).

[8] The Horthemels family, originally from the Netherlands, were followers of the Dutch theologian Cornelis Jansen and had links with the Parisian abbey of Port-Royal des Champs, the centre of Jansenist thought in France.

[2] His funeral is again recorded in some detail in the parish register of the church of Saint-Sulpice, Paris, as quoted in Eugène Piot's Le Cabinet de l'amateur.

Apart from describing him as painter to the king in the Royal Academy of Painting and Sculpture, comptroller of clergy stipends and of poultry, the register entry says that Belle was the husband of Marie-Nicole Hortemels and had died at his house in the rue du Four on the previous day, 21 November.

His age is given as "about 60 years, 10 months, 8 days", and it is also recorded that the funeral was attended by Clément Louis Marie Anne Belle and "N. Belle, privately baptized, aged 7 years", sons, and by "Fréderic-Eustache-Auguste Hortemels, copperplate engraver, Denis Hortemels, bookseller, Nicolas Tardien and Charles-Nicolas Cochin, engravers to the king, both brothers-in law to the deceased".

When he died in 1806, he was described as "Rector of the Special School of Painting, Sculpture, Architecture and Engraving, and Professor of Design to the Imperial Manufactury of Gobelins".