The Earliest Known Datable Runic Inscription Survives on the Vimose Comb

The Vimose Comb, from Vimose, Funen, Denmark, is considered the oldest datable Elder Futhark runic inscription in late Proto-Germanic or early Proto-Norse. 

This and other slightly later items from Vimose dating from circa 200-300 CE, are known as the Vimose inscriptions.