As an English name, it has been used occasionally since the 12th century. It is the name of a central character in Shakespeare's play The Two Gentlemen of Verona (1594).
Though in use elsewhere in Europe, the name was very rare in the English-speaking world until the 19th century, when Queen Victoria began her long rule of Britain. She was named after her mother, who was of German royalty. Many geographic areas are named after the queen, including an Australian state and a Canadian city.
This name was later borne by three other English kings, as well as rulers of Scotland, Sicily (of Norman origin), the Netherlands and Prussia. Other famous bearers include William Wallace, a 13th-century Scottish hero, and William Tell, a legendary 14th-century Swiss hero (called Wilhelm in German, Guillaume in French and Guglielmo in Italian). In the literary world it was borne by dramatist William Shakespeare (1564-1616), poet William Blake (1757-1827), poet William Wordsworth (1770-1850), dramatist William Butler Yeats (1865-1939), author William Faulkner (1897-1962), and author William S. Burroughs (1914-1997).
In the American rankings (since 1880) this name has never been out of the top 20, making it one of the most consistently popular names (although it has never reached the top rank). In modern times its short form, Liam, has periodically been more popular than William itself, in the United Kingdom in the 1990s and the United States in the 2010s.