This chapter discusses the obligation of Muslims to migrate (i.e. hijra) from territories ruled by non-Muslims to those that constitute part of Muslim territory (the Dār al-Islām) in the context of the expansion of the Russian Empire into Caucasia in the late nineteenth century CE. Specifically, it focuses on al-Risāla al-Sharīfa of ʿAbd al-Raḥmān al-Thughūrī (d. 1299/1882), who argues in favour of the obligation to migrate, citing various incidents from the early history of Islam as evidence. The Russian annexation of Dagestan, Chechnya in 1859 and the subsequent conquest of the whole territory of Circassia in 1864 brought large Muslim populations under Russian rule. Faced with changes to the operation of Islamic legal institutions and not inconsiderable persecution, Caucasian Muslim jurists sought to address the question of Muslims’ status as subjects of a powerful non-Muslim state.