Xianbei in the context of "Northern Zhou"

Mongolia is a landlocked country in East Asia. Bordered by Russia to the north and China to the south and southeast, it covers an area of 1,564,116 square kilometres (603,909 square miles), making it the 18th-largest country in the world and the second largest landlocked country after Kazakhstan, as well as the largest landlocked country that does not border an inland sea. With a population of 3.5 million, it is the world's most sparsely populated sovereign state. The country constitutes a significant portion of the Mongolian Plateau, and its natural environment is characterized by grassy steppe, mountains to the north and west, and the Gobi Desert to the south. Ulaanbaatar, the capital and largest city, is home to roughly half of the country's population.

The territory of modern-day Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the First Turkic Khaganate, the Second Turkic Khaganate, the Uyghur Khaganate and others. In 1206, Genghis Khan founded the Mongol Empire, which became the largest contiguous land empire in history. His grandson Kublai Khan conquered China proper and established the Yuan dynasty. After the collapse of the Yuan, the Mongols retreated to Mongolia and resumed their earlier pattern of factional conflict, except during the era of Dayan Khan and Tumen Zasagt Khan.

The Eurasian Steppe, also called the Great Steppe or The Steppes, is the vast steppe ecoregion of Eurasia in the temperate grasslands, savannas and shrublands biome. It stretches through Manchuria, Mongolia, Xinjiang, Kazakhstan, Siberia, European Russia, Ukraine, Moldova, Romania, Bulgaria, Hungary and Slovakia.

Since the Paleolithic age, the Steppe Route has been the main overland route between Eastern Europe, North Asia, Central Asia and East Asia economically, politically, and culturally. The Steppe route is a predecessor not only of the Silk Road, which developed during antiquity and the Middle Ages, but also of the Eurasian Land Bridge in the modern era. It has been home to nomadic empires and many large tribal confederations and ancient states throughout history, such as the Xiongnu, Scythia, Cimmeria, Sarmatia, Hunnic Empire, Sogdia, Xianbei, Mongol Empire, Magyar tribes, and Göktürk Khaganate.

Tengrism (also known as Tengriism, Tengerism, or Tengrianism) is a belief system originating in the Eurasian steppes, based on shamanism and animism. It generally involves the titular sky god Tengri. According to some scholars, adherents of Tengrism view the purpose of life as to be in harmony with the universe.

It was the prevailing religion of the Göktürk, Hun, Xianbei, Bulgar, Xiongnu, Yeniseian and Mongolic peoples, as well as the state religion of several medieval states such as the First Turkic Khaganate, the Western Turkic Khaganate, the Eastern Turkic Khaganate, Old Great Bulgaria, the First Bulgarian Empire, Volga Bulgaria, Khazaria, and the Mongol Empire. In the Irk Bitig, a ninth century manuscript on divination, Tengri is mentioned as Türük Tängrisi (God of Turks). According to many academics, Tengrism was, and to some extent still is, a predominantly polytheistic religion based on the shamanistic concept of animism, and was first influenced by monotheism during the imperial period, especially by the 12th–13th centuries. Abdulkadir Inan argues that Yakut and Altai shamanism are not entirely equal to the ancient Turkic religion.

The Rouran Khaganate (Chinese:柔然; Róurán), also known as Ruanruan or Juan-juan (蠕蠕; Ruǎnruǎn) (or variously Jou-jan, Ruruan, Ju-juan, Ruru, Ruirui, Rouru, Rouruan or Tantan), was a tribal confederation and later state. The Rouran state was undoubtedly multi-ethnic. As the ancient sources regard the Rouran as a separate branch of the Xiongnu Book of Song and Book of Liang connected Rourans to the earlier Xiongnu while the Book of Wei connected them to Proto-Mongolic Donghu. The Rouran supreme rulers used the title of khagan, a popular title borrowed from the Xianbei. The Rouran Khaganate lasted from the late 4th century until the middle 6th century with territory that covered all of modern-day Mongolia and Inner Mongolia, as well as parts of Manchuria in Northeast China, Eastern Siberia, Xinjiang, and Kazakhstan. The Hephthalites were vassals of the Rouran Khaganate until the beginning of the 5th century, with the royal house of Rourans intermarrying with the royal houses of the Hephthalites. The Rouran Khaganate ended when they were defeated by a Göktürk rebellion at the peak of their power, which subsequently led to the rise of the Turks in world history.

Their Khaganate overthrown, some Rouran remnants possibly became Tatars while others possibly migrated west and became the Pannonian Avars (known by such names as Varchonites or Pseudo Avars), who settled in Pannonia (centred on modern Hungary) during the 6th century. These Avars were pursued into the Byzantine Empire by the Göktürks, who referred to the Avars as a slave or vassal people, and requested that the Byzantines expel them. While this Rouran-Avars link remains a controversial theory, a recent DNA study has confirmed the genetic origins of the Avar elite as originating from the Mongolian plains. Other theories instead link the origins of the Pannonian Avars to peoples such as the Uar.

The Khitan people (Khitan small script: ; Chinese: 契丹; pinyin: Qìdān) were a historical nomadic people from East Asia and parts of North Asia who, from the 4th century, inhabited an area corresponding to parts of modern Mongolia, Northeast China and the Russian Far East.

As a people descended from the proto-Mongols through the Xianbei, Khitans spoke the now-extinct Khitan language, a Para-Mongolic language related to the Mongolic languages. The Khitan people founded and led the Liao dynasty (916–1125), which dominated a vast area of Siberia, Mongolia and Northern China. The Khitans of the Liao dynasty used two independent writing systems for their language: Khitan small script and Khitan large script.

The Greater Khingan Range or Da Hinggan Range (simplified Chinese: 大兴安岭; traditional Chinese: 大興安嶺; pinyin: Dà Xīng'ān Lǐng; IPA: [tâ ɕíŋ.án.lìŋ]) is a 1,200-kilometer-long (750 mi) volcanic mountain range in the Inner Mongolia region of Northeast China.It was originally called the Xianbei Mountains, which later became the name of the northern branch of the Donghu, the Xianbei.

The Shanhai Pass (simplified Chinese: 山海关; traditional Chinese: 山海關; pinyin: Shānhǎi Guān; lit. 'Mountain Sea Pass') is a major fortified gateway at the eastern end of the Great Wall of China and one of its most crucial fortifications, as the pass commands the narrowest choke point in the strategic Liaoxi Corridor, an elongated coastal plain between the Yan Mountains foothills and the Bohai Sea, which is the only easily traversable landway between North and Northeast China. It is located in present-day Shanhaiguan District, Qinhuangdao, Hebei province, on the east bank of the Shi River, with defensive walls stretching from the Yan Mountains all the way to the shores of the Liaodong Bay.

Throughout Chinese history, garrisons around the pass served as frontline defensive outposts against raids and incursions into the North China Plain by various non-Sinitic ethnic groups from the Northeast (also known as Manchuria since the 19th century), including the Dongyi, Donghu (Xianbei and Wuhuan), Khitan and Jurchen (Manchus). The current Shanhai Pass was built during the early Ming dynasty as the easternmost fortification of the Ming Great Wall, and was extensively reinforced after Yongle Emperor moved the capital from Nanjing to Beijing following the Jingnan campaign, making it the most important defensive barrier in all of China, as it shielded the heartland region around the imperial capital. The pass' strategic location dictated that without mounting a costly direct siege, the only way an invading army can get past the pass' defense was to circumvent it around the north through a few treacherously narrow mountain passes deep within the Yan Mountains, which would make it very difficult to maintain supply lines and thus any sizeable invasions. This defensive significance therefore earned the pass the famous nickname "Greatest Pass Under Heaven" (天下第一关).