Sire was a respectful form of address for reigning kings in Europe. It was used in Belgium, France, Italy, Germany, Sweden, Spain, and the United Kingdom. Historically, Sire had a wider usage. During the Middle Ages, Sire was generally used to address a superior, a person of importance or in a position of authority, or the nobility in general. Sire was a respectful form of address for reigning kings in Europe. It was used in Belgium, France, Italy, Germany, Sweden, Spain, and the United Kingdom. Historically, Sire had a wider usage. During the Middle Ages, Sire was generally used to address a superior, a person of importance or in a position of authority, or the nobility in general. The words 'sire' and 'sir', as well as the French '(mon)sieur', share a common etymological origin, all ultimately being related to the Latin senior. The female equivalent form of address is dame or dam.