Ogham Letter Or

It marks the OI/OE vowel pair.

In the medieval letter-key tradition, Ór is an indirect poetic name for the OI/OE pair: two vowels in one syllable, not a tree name. Forfeda (“extra letters”) added signs for later Irish sounds or combinations absent from Ogham’s original set.

Ogham was devised to write early Irish and may have drawn on Latin writing, but its signs represent Irish sounds. The oldest datable stones reach the late fourth century; fifth- and sixth-century inscriptions record names, memorials, and territory. From the eighth century, manuscripts used it for grammar and coded notes; Scotland and the Isle of Man kept stone use until the Viking period ended. In 20th- and 21st-century revival, it signals Irish or Gaelic antiquarian interest. Fonts may omit the central line; stones run bottom-to-top, manuscripts left-to-right.