While the earliest Old English texts represent this phoneme with the digraph ⟨uu⟩, scribes soon borrowed the rune wynn ᚹ for this purpose. It remained a standard letter throughout the Anglo-Saxon era, eventually falling out of use (perhaps under the influence of French orthography) during the Middle English period, circa 1300. It was replaced with ⟨uu⟩ once again, from which the modern ⟨w⟩ developed.
It is not continued in the Younger Futhark, but in the Gothic alphabet the letter 𐍅 w is called winja, allowing a Proto-Germanic reconstruction of the rune’s name as *wunjô “joy”.
It is one of the two runes (along with þ) to have been borrowed into the English alphabet (or any extension of the Latin alphabet). A modified version of the letter wynn called vend was used briefly in Old Norse for the sounds /u/, /v/, and /w/.
As with þ, the letter wynn was revived in modern times for the printing of Old English texts, but since the early 20th century the usual practice has been to substitute the modern ⟨w⟩.