My research is based on the aristocracy of France and its neighbours in the 16th-18th centuries, and the notion of frontier identities. In particular, I am working on a new history of the Duchy of Lorraine, a formerly independent state between France and Germany. My previous book, The Society of Princes, explored the relationship of the cadet branch of the House of Lorraine, the Guise, with the court of Louis XIV at Versailles.
I am also interested in early modern royal courts, in France and elsewhere. I particularly focus on members of royal families besides the king: his wife, his brother, his mother, his cousins, and am completing a comparative study of the four second sons (the 'spares') known at the French court simply as 'Monsieur'. I was a consultant for the television programme 'Versailles' regarding the character of Philippe.
I am on the executive committee for the Society for Court Studies, and senior editor of its journal, The Court Historian.
Fellow of the Royal Historical Society