"Ŭ", or "ŭ", is a vowel and letter in the Esperantoalphabet. Since each letter in Esperanto has a consistent sound, this letter is always pronounced the same; its sound is represented by [w] in SAMPA.
... Holy Roman Emperor (as Charles V) from 1519-1558; he was also King of Spain from 1516-1556 -- officially as Charles I of Spain, although often referred to as Charles V ...