A dhimmi refers to a non-Muslim subject of the Ottoman Empire. Derived from Islamic legal conceptions of membership to society, non-Muslims ‘dhimmis’ were afforded protection by the state and did not serve in the military, in return for specific taxes. The dhimmi status was legally abolished in 1839 with the Hatt-ı Şerif of Gülhane and was formalized with the 1869 Ottoman Law of Nationality as part of wider Tanzimat Reforms. Regardless of these official changes, in various places within the Empire non-Muslim subjects faced various forms of institutional discrimination.
Sources:
M. Şükrü Hanioğlu, A Brief History of the Late Ottoman Empire (Princeton: Princeton University Press, 2008).