12, 1828. In the course of the Crimean War, the Cossacks foiled attempts by allied forces to land on the Taman Peninsula, whilst the 2nd and 5th plastun battalions took part in the Defence of Sevastopol (1854–1855). As the years went by, the Black Sea Cossacks continued their systematic penetration into the mountainous regions of the Northern Caucasus. Taking an active part in the finale of the Russian conquest of the Northern Caucasus (1817–1864), they settled regions as these were conquered. To aid them, a total of 70,000 additional ex-Zaporozhians from the Bug, Yekaterinoslav, and finally the Azov Cossack Host migrated there in the mid 19th century. All three hosts needed to be removed to vacate space for the colonisation of New Russia, and with the increasing weakness of the Ottoman Empire as well as the formation of independent buffer states in the Balkans, the need for further Cossack defensive presence in New Russia had ended. They migrated to the Kuban in 1860 and merged with the Caucasus Line Cossack Host, which consisted of migrated Don Cossack elements. Finally, in 1864, the Black Sea Cossacks and the Azov Cossacks were united into the Kuban Cossack Host, ninety years after the destruction of the Zaporozhian Sich. Administration Upon creation, the territory of the host was governed by the military government. Later, a dedicated military executive office was created, which was headed by the host's ataman. In military matters, this office was subordinated to Kherson's military governor and, since 1802, to the Crimean Inspectorate. In civil matters, the office was subordinated to the Governor of Taurida Governorate. References Sources 18th century in the Zaporozhian Host Cossack hosts