Robert I was the last sovereign Duke of Parma and Piacenza from 1854 until 1859, when the duchy was annexed to Sardinia-Piedmont during the Risorgimento. He was a member of the House of Bourbon-Parma and descended from Philip, Duke of Parma, the third son of King Philip V of Spain and Queen Elisabeth Farnese.

Dom Miguel I, nicknamed "the Absolutist", "the Traditionalist" and "the Usurper", was the King of Portugal between 1828 and 1834. He was the seventh child and third son of King John VI and Queen Carlota Joaquina.