According to the Haran Gawaita, a text that tells the history of the Mandaean people, the Mandaeans arrived in the Parthian Empire during the reign of Artabanus II, and later moved to southern Babylonia. This would make the Iraqi presence of Mandaeans approximately 2000 years old, making it the third oldest continually-practiced faith in Iraqi society after Zoroastrianism and Judaism. However, Mandaeans believe their religion predates Judaism and Christianity as a monotheistic faith tracing it back to their first prophet Adam. Until the 2003 Iraq war, there were about 60,000 estimated Mandaeans living in Iraq. The oldest independent confirmation of Mandaean existence in the region is Kartir's inscription at Naqsh-e Rajab. The Mandaean faith is commonly known as the last surviving Gnostic religion. John the Baptist, known as "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 Amarah, Nasiriyah and Basra. Besides these southern regions and Ahvaz in Iran, large numbers of Mandaeans can be found in Baghdad, giving them easy access to the Tigris River.