The Old English letter called wynn represented the /w/ sound.
Wynn is written Ƿ in uppercase and ƿ in lowercase. It belonged to the Old English alphabet and was adapted from the Anglo-Frisian Futhorc, the runic writing system used by early Germanic-speaking peoples. Its name is related to a rune meaning “joy” or “bliss.”
Early Old English manuscripts sometimes wrote the /w/ sound with the Latin-letter combination uu. Scribes later revived wynn as a single character, making it a practical part of written Old English. It remained in regular use through the Anglo-Saxon period before gradually disappearing during the Middle English period, around the thirteenth century.
After wynn fell out of use, writers used alternatives including uu and a ligature-like form that eventually developed into the modern letter w. The letter is therefore historically important: modern w is not simply an unchanged Latin character inherited from classical Latin. Wynn is sometimes confused with yogh, ash, or eth, but those letters represented different sounds or linguistic functions.