In 2004, royalty gathered at the Basilica of Saint Denis for what looked like a state funeral, yet the object at its center was a small mummified human heart, its identity finally confirmed by modern science. It belonged to Louis Charles, the boy known to history as Louis XVII, technically king of France who never ruled a day.

This deep dive digs beneath the sweeping dates of the French Revolution to show how a child became a pawn in one of history's most volatile political shifts, examined impartially as historical fact.

• His birth at Versailles, becoming dauphin at four, and the family's forced relocation and failed flight to Varennes.
• Imprisonment in the Temple Tower and the execution of his father in 1793.
• His separation from his mother and a program of psychological abuse under the shoemaker Antoine Simon. ...