The grand ducal family of Luxembourg constitutes the House of Luxembourg-Nassau,[1] headed by the sovereign grand duke, and in which the throne of the grand duchy is hereditary. It consists of heirs and descendants of the House of Nassau-Weilburg, whose sovereign territories passed cognatically from the House of Nassau to the House of Bourbon-Parma, itself a branch of the Spanish royal house which is agnatically a cadet branch of the House of Capet that originated in France, itself a derivative dynasty from the Robertians and the Karlings and the founding house of the Capetian dynasty.