Perthro

The p-rune ᚲ is the rune in the Elder Futhark runic alphabet that represents the sound /p/ (voiceless bilabial stop). It does not appear in the Younger Futhark. In the Anglo-Saxon runic poem, it is called Peorð and is mystically glossed as follows:

Peorð is a source of rest and joy for the great, where warriors sit joyfully in the beer hall together.

The name is not clearly traceable in Old English, meaning no word similar to Peorð is known in this language. According to a manuscript by Alcuin from the 9th century (Codex Vindobonensis 795), the letters 𐍀 p (based on Greek Π) and 𐌵 q (an inverted Π) are called pairþra and qairþra. One of these names is clearly derived from the other. However, the names are not understood in Gothic, and it is unclear which is derived from which, though it is known that the Elder Futhark had a p-rune, but no q-rune. It seems evident that Peorð is related to pairþra. The Anglo-Saxon Futhorc adopted a similar approach for the addition of a labiovelar rune, ᛢ cƿeorð, which is based both in form and name on Peorð, but it is unclear whether the Gothic runes had a similar variant of p or whether the labiovelar letter was a creation of Ulfilas from the 4th century.

The common Germanic name could refer to a pear tree (or perhaps a general fruit tree). Based on the context provided in the runic poem, "rest and joy," a common speculative interpretation is that the intended meaning is "pear tree" as the material for a woodwind instrument or a "play box" or wooden play figures.

Phonologically, Peorð can be reconstructed as proto-Germanic perðu, perþō, or *perþaz. The expected proto-Germanic term for "pear tree" would be *pera-trewô (*pera, however, is a post-proto-Germanic loanword, either from West Germanic or Common Germanic, if the Gothic *pairþra meant "pear tree," from the Vulgar Latin *pirum (plural pira), of unknown origin). The Ogham letter name Ceirt, which is glossed as "apple tree," may itself be a loan from Germanic into Irish.

The earliest mention of the rune is found in the Futhark sequence of the Kylver Stone (circa 400 AD). The earliest example in a linguistic context (as opposed to an abecedarium) is already found in Futhorc, in the Kent II, III, and IV coin inscriptions (the personal names pada and æpa/epa), dated around 700 AD. On the coffin of Saint Cuthbert (698 AD), a p-rune replaces the Greek Ρ. On the Yew Stock of Westeremden (circa 750 AD), it is written op hæmu "at home" and up duna "on the hill."

Looijenga (1997) speculates that the p-rune evolved as a variant of the b-rune, parallel to the secondary nature of the Ogham peith. The uncertainty surrounding the rune is a consequence of the rarity of the phoneme p in Proto-Germanic, which in turn is due to the scarcity of its parent phoneme b in Proto-Indo-European.

The rune is no longer present in the Younger Futhark, which expresses /p/ with the b-rune, for example, on the Viking Age Skarpåker stone.

Jörð skal rifna ok upphiminn
"Earth shall be torn and the sky above."