A portrait miniature is a miniature portrait painting, usually executed in gouache, watercolour, or enamel. Portrait miniatures developed out of the techniques of the miniatures in illuminated manuscripts, and were popular among 16th-century elites, mainly in England and France, and spread across the rest of Europe from the middle of the 18th-century, remaining highly popular until the development of daguerreotypes and photography in the mid-19th century. They were especially valuable in introducing people to each other over distances; a nobleman proposing the marriage of his daughter might send a courier with her portrait to visit potential suitors. Soldiers and sailors might carry miniatures of their loved ones while traveling, or a wife might keep one of her husband while he was away.