This is Philip II of Spain. When Bloody Mary saw this painting, she fell in love.
" Mary rejected Edward Courtenay, 1st Earl of Devon, as a prospect when her cousin Charles V suggested she marry his only son, the Spanish Prince Philip, later Philip II of Spain. It is said that upon viewing the Titian full-length portrait of Philip now in the Prado, which had been sent to her, Mary declared herself to be in love with him." (wiki: "Mary I of England" - Bloody Mary)