Nicolas Henri, Duke of Orléans

Monsieur d'Orléans (16 April 1607 – 17 November 1611) was the second son and fourth child of Henry IV of France and his second consort, Marie de' Medici. Commonly ascribed the names Nicolas or Nicolas Henri and the title Duke of Orléans, he was neither baptised nor invested as such during the course of his short life. He was betrothed to Marie de Bourbon, Duchess of Montpensier, heiress to vast lands of the extended House of Bourbon. After his father's death in 1610, he was heir presumptive to his older brother, Louis XIII. Of frail health, he died of seizures brought on by hydrocephalus at the aged four, whereupon his title and betrothal were transferred to his younger brother Gaston.