Isabella of Portugal was the empress consort of her husband Charles V, Holy Roman Emperor, King of Spain, Archduke of Austria, and Duke of Burgundy. She was Queen of Spain and Germany, and Lady of the Netherlands from 10 March 1526 until her death in 1539, and became Holy Roman Empress and Queen of Italy in February 1530. She acted as regent of Spain during her husband's long absences.

Manuel I, known as the Fortunate, was King of Portugal from 1495 to 1521. A member of the House of Aviz, Manuel was Duke of Beja and Viseu prior to succeeding his cousin, John II of Portugal, as monarch. Manuel ruled over a period of intensive expansion of the Portuguese Empire owing to the numerous Portuguese discoveries made during his reign. His sponsorship of Vasco da Gama led to the Portuguese discovery of the sea route to India in 1498, resulting in the creation of the Portuguese India Armadas, which guaranteed Portugal's monopoly on the spice trade. Manuel began the Portuguese colonization of the Americas and Portuguese India, and oversaw the establishment of a vast trade empire across Africa and Asia.