Runology is the study of the runic alphabets, runic inscriptions, runestones, and their history. Runology forms a specialised branch of Germanic linguistics.
The earliest runic inscriptions date from around 150 AD. The characters were generally replaced by the Latin alphabet as the cultures that had used runes underwent Christianisation, by approximately 700 AD in central Europe and 1100 AD 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 decorative purposes in Dalarna and on Runic calendars.
The three best-known runic alphabets are the Elder Futhark (around 150–800 AD), the Anglo-Saxon Futhorc (400–1100 AD), and the Younger Futhark (800–1100 AD). The Younger Futhark is divided further 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 stavlösa or Hälsinge runes (staveless runes). The Younger Futhark developed further into the Medieval runes (1100–1500 AD), and the Dalecarlian runes (around 1500–1800 AD).