Originally a short form of Germanic names containing the element wald meaning "rule". In the Middle Ages this name became the basis for a surname. Its present use in the English-speaking world is usually in honour of Ralph Waldo Emerson (1803-1882), an American poet and author who wrote on transcendentalism. He was (probably) named after the 12th-century Christian radical Peter Waldo, who was from Lyons in France. Though Waldo and his followers, called the Waldensians, were declared heretics at the time, they were later admired by Protestants.