The oldest known form and arrangement of Runic letters, the Elder Futhark runes, are estimated by the British Museum to have been in use by the Vikings around 200 A.D. Some believe it to be much earlier. In Norse, the Elder Futhark is read from right to left. "F U T H A R K" is the first 6 symbols of the Runic alphabet (note "th" is one letter).
The Runic alphabet is phonetic, each letter represents a sound, so double consonants are not used. Words spelled with pp, dd, ll, etc. would be spelled using a single p, d, or l in Runes.