The Aklo language is a fictional language system which appeared in Arthur Machen's short story The White People. H.P. Lovecraft used the Aklo in a number of his stories, most notably The Dunwich Horror and The Diary of Alonzo Typer. It appears as a key element of Alan Moore's Cthulhu Mythos work The Courtyard.
The Aklo language and script was first used by the Serpent Men some 1.5 million years ago, during the Pleistocene epoch. It is unlikely that this langauge was in every day use. It may be that Aklo was a ritual language only used by the priestly castes in ceremonies. There is a possiblity that the Serpent Men learnt the Aklo from the Old Ones (the lesser children of Yog-Sothoth) since those beings are known to respond to summons spoken in Aklo. To this day the Aklo language is still employed in certain spells and rituals.
Allthough Aklo can be used for communication its primary usage is in incantations and prayers. Below is a list of some of the magical rites the Aklo is employed in.
- The Aklo Unveilings are a collection of 48 revelations recorded by the Aklo. There is said to be a 49th Unveiling which mankind will only learn when Glaaki calls humanity to him.
- The Aklo Formulii are a collection of incantations connected with the summoning, banishing and controlling of certain extra dimensional beings. The Third Aklo Formula can be used to make invisible and immaterial entities reveal their physical form.
Since the Aklo language is still in use today certain cultists and sorcerers may have records and codexs in this langauge. One of the best known public records of the Aklo lanaguge is the Unaussprechlichen Kulten which contains a key to deciphering the Aklo lettering system and a rudimentary dictionary.