Runes are the letters in a set of related alphabets known as runic alphabets which were used to write various Germanic languages before the adoption of the Latin alphabet and for specialized purposes thereafter. The Scandinavian variants are also known as futhark or fuþark (derived from their first six letters of the alphabet: F, U, Þ, A, R, and K); the Anglo-Saxon variant is futhorc or fuþorc (due to sound changes undergone in Old English by the same six letters). Runology is the study of the runic alphabets, runic inscriptions, runestones, and their history. Runology forms a specialized branch of Germanic linguistics.
The earliest runic inscriptions date from around AD 150. The characters were generally replaced by the Latin alphabet as the cultures that had used runes underwent Christianization by around AD 700 in central Europe and by around AD 1100 in Northern Europe. However, the use of runes persisted for specialized purposes in Northern Europe. Until the early 20th century runes were used in rural Sweden for decoration purposes in Dalarna and on Runic calendars.
The three best-known runic alphabets are the Elder Futhark (around 150–800), the Anglo-Saxon Futhorc (400–1100), and the Younger Futhark (800–1100). The Younger Futhark is further divided into the long-branch runes (also called Danish, although they were also used in Norway and Sweden), short-branch or Rök runes (also called Swedish-Norwegian, although they were also used in Denmark), and the stavesyle or Hälsinge runes (staveless runes). The Younger Futhark developed further into the Marcomannic runes, the Medieval runes (1100–1500), and the Dalecarlian runes (around 1500–1800).
Historically, the runic alphabet is a derivation of the Old Italic alphabets of antiquity, with the addition of some innovations. Which variant of the Old Italic family in particular gave rise to the runes is uncertain, suggestions including Raetic, Etruscan or Old Latin candidates. All these scripts at the time had the same angular letter shapes suited for epigraphy which would become characteristic of the runes. The process of transmission of the script (the oldest inscriptions being found in Denmark and Northern Germany, not near Italy) is also unknown. A "West Germanic hypothesis" suggests transmission via Elbe Germanic groups, while a "Gothic hypothesis" assumes transmission via East Germanic expansion.