Mandaeism
The Mandaean faith has existed in Iraq since the reign of Artabanus V of Parthia according to the Haran Gawaitha (secret wanderings) scroll of secondary Mandaean writ. This would make the Iraqi presence of Mandaeans at least 1,800 years old, making it the third oldest continually professed faith in Iraqi society after Zoroastrianism and Judaism. There are more Mandaeans in Iraq than there are Zoroastrians or Jews combined. In Iraq estimates of around 60,000 have been made. The oldest independent confirmation of Mandaean existence in the region is the Kartir inscription. The Mandaean faith is commonly known as the last surviving Gnostic faith and its adherents believe it to be the oldest faith on Earth, with at least some scholarly support for it being as old if not older than Christianity perhaps even being a major influence in the development of heterodox Jewish circles which eventually led to the formation of Christian beliefs, practices, rituals and theology. John the Baptist or Yahia Yuhanna is considered to have been the final Mandaean prophet and first true Ris'Amma, or Ethnarch, of the Mandaean people. Most Iraqi Mandaeans live near waterways because of the practice of total immersion (or baptism) in flowing water every Sunday. The highest concentrations are in the Mesene province with headquarters in Amarah, Qalat Saleh and Basra. Besides these southern regions bordering Kuzistan in Iran, large numbers of Mandaeans can be found in Baghdad in the Dweller's Quarters, giving them easy access to the Tigris River.
Read more about this topic: Religion In Iraq