Ancient Medieval Modern Yarsanism (Kurdish: یارسان, romanized: Yarsan), Ahl-e Haqq (Kurdish: ئەهلی حەق, romanized: Ehl ê Ḧeq,;[4][5] Persian: اهل حق), or Kaka'i,[3] is an inherited, syncretic religion founded by Sultan Sahak in the late 14th century in western Iran.

[10] Their central religious book is called the Kalâm-e Saranjâm, written in the 15th century and based on the teachings of Sultan Sahak.

[11] The main urban centers of the religion are Sahneh, Kerend-e Gharb and Gahvareh, and other important cities include Kermanshah, Sarpol-e Zahab and Qasr-e Shirin.

[12] In Iraq, Yarsan followers mainly live in Mosul, Kirkuk, Kalar, Khanaqin, Erbil, Sulaymaniyah, and Halabja.

From the Yarsani point of view, the universe is composed of two distinct yet interrelated worlds: the internal (bātinī) and the external (zāhirī), each having its own order and rules.

These traditions are said to have been written down by Pir Musi, one of the seven companions of Sultan Sahak (also the angel in charge of recording human deeds).

Also important to the Goranî is the Daftar-e kezana-ye Perdivari (Book of the Treasure of Perdivar), a collection of twenty six mythological poems or kalams.

[24] The sayings attributed to Sultan Sahak are written in Gorani Kurdish, the sacred language of the Ahl-e Haqq, which also is known as Hawrami dialects.

After Sultan Sahak's time another four khandans were established, namely Atesh Bag, Baba Heydar, Zolnour and Shah Hayas.

Say-yeds are the only ones allowed to have full access to the religious texts of Yarsanism, and have traditionally competed with each other to have the largest number of followers.

An excerpt from the French Review of the Muslim World[32] describes the difficulty in nomenclature for Yarsanism and related Shi'ite mysticism.

Like any religion, the one we are dealing with considers itself to be the only true and orthodox one, and it is natural that its adherents give themselves the name of "People of Truth" (Ahlé-Haqq or Ahlé-Haqîqat).

Still, the name Ahlé-Haqq to refer to the sect of our particular interest has every advantage over appellations such as "Gholat", "Alî-Allâhi", and "Noséïri" that the Muslims and most European travellers use in speaking of them.

Finally, the name "Noséïri" belongs to that well-defined Syrian religion, which, despite some resemblances with the doctrines of the Ahlé-Haqq (the worship of Ali, the communion, etc.

The final stage supersedes the previous ones, which frees Ahl-e Haqq from observing the shari'a rules incumbent on Muslims.

The Ahl-i Haqq neither observe Muslim rites, such as daily prayers and fasting during the month of Ramadan, nor share Islamic theology and sacred space, such as belief in the day of resurrection and sanctity of the mosque.

These militants have persecuted Yarsanis during the Iraq conflict, possibly prompting some Iraqi Yarsan community leaders to declare in 2013 that their people were actually Muslims to avoid sectarian attacks.