A poll tax.
Several poll taxes were levied throughout the Middle East from the time of the Muslim conquests (seventh century). Caliph Umar II (717–720 c.e.) established the principle that they should be levied only on non-Muslims. Islam exempted women, children, and the disabled or unemployed from the tax.
In 1855, the Ottoman Empire abolished the tax, as part of reforms to equalize the status of Muslims and non-Muslims. It was replaced, however, by a military-exemption tax on non-Muslims, the Bedel-i Askeri.
see also bedel-i askeri.