The Republic of North Ossetia – Alania is a federal subject of Russia (a republic), located in the Caucasus region. Early history The territory of North Ossetia has been inhabited for thousands of years, being both a very fertile agricultural region and a key trade route through the Caucasus Mountains. The ancestors of the present inhabitants were a people called the Alans, a warlike nomadic people who spoke an Iranian language. Part of the Alan people eventually settled in the Caucasus around the 7th century AD. By about the 9th century, the kingdom of Alania had arisen and had been converted to Christianity by Byzantine missionaries. An archbishopric was established in western Alania under the authority of the Patriarchate of Constantinople, and many large churches were constructed (Zelenchuk churches, Shoana Church, Senty Church). Alania became a powerful state in the Caucasus, profiting greatly from the legendary Silk Road to China, which passed through its territory. From the Middle Ages onwards, Alania was beset by external enemies and suffered repeated invasions. The invasions of the Mongols and Tatars in the 13th century decimated the population, who were now known as Ossetians. Islam was introduced in the 17th century through the Kabardians, a Muslim Caucasian people. Incursions by the Khanate of Crimea and the Ottoman Empire eventually pushed Alania/Ossetia into an alliance with Russia in the 18th century. North Ossetia was among the first areas of the northern Caucasus to come under Russian domination, starting in 1774, and the capital, Vladikavkaz, was the first Russian military outpost in the region. By 1806, Ossetia was completely under Russian control. Imperial Russia The arrival of Imperial Russia led to the rapid development of the region, with industries founded and road and rail connections built to overcome Ossetia's isolation. The Georgian Military Road, which is still a crucial transport link across the mountains, was built in 1799 and a railway line was built from Vladikavkaz to Rostov-on-Don in Russia proper. The Ossetians' traditional culture inevitably underwent some russification, but their new connections with Russia and the West helped to boost local culture; the first books in the Ossetian language were printed in the late 18th century. In 1830, a military campaign led by General Ivan Abkhazov brought North Ossetia under tighter control of the Russian Empire. The area became part of the Terskaya Region of Russia in the mid-19th century. Russian Revolution and USSR After