The history of ancient Mongolia dates back to third century BC when the Xiongnu came to power among many other nomadic tribes.
Due to illiteracy and nomadic lifestyle, little was recorded by Huns of themselves. They first appear in recorded Chinese history as "barbarians" against whom the walls were built. Those walls later became known as the Great Wall of China.
There have been several empires in Mongolia after the Hun Nu. For example, the A Tureg Empire around 650AD, with its capital approximately 110km north of Har Horin (Kharkhorum). There was also the Uighur Empire, with its capital Har Bulgas (Khar Bulgas or Xar Bulgas) near Har Horin. The Khitans who controlled North China around 1000AD as the Liao Dynasty had an administrative center (Har Bukh) 120km to the northeast. The Government of Turkey has been promoting some Turkish Empire monuments and there is a museum of artifacts at the Bilge Khaan site.
The struggle for mere existence and power over other tribes continued until the time of Genghis Khan. Chinggis Khan, as he is known in Mongolia, came to power and united the warring tribes under the Great Mongol Empire in 1206. He was proclaimed Genghis Khan (Chingis Haan), meaning ruler of all Mongol tribes. The Mongolian Empire was extended all the way to eastern Europe under Genghis Khan and to all of China and Central Asia, among other parts under his successors (including his grandson Kublai Khan), becoming the largest continuous empire in history with thirty-three million square kilometers (about thirteen million square miles) of extension. After years of hegemony and exercise of a great connection between Eastern and Western civilizations, the empire split into four kingdoms (or Khanates) through Eurasia, each of which lately achieved nearly total independence. The easternmost of these kingdoms was called the Yuan Dynasty and included Mongol native land and much of China. After times of dominance over China, the Mongols were driven back to the steppes by the Chinese Ming Dynasty under Emperor Hongwu. They were later conquered by the Manchurian-Chinese Emperors Kangxi and Qianlong of the Qing Dynasty.
An independent Mongol nation would only emerge again in 1924 but was not recognised by China until 1945, as the Chinese were forced to grant independence to Outer Mongolia by the Soviet Union, in exchange for Soviet assistance in fighting the Japanese invasion. Thus, the historic region of Mongolia was split into two, with Outer Mongolia becoming the independent nation of Mongolia, while Inner Mongolia remained a province of China. Since that time, Mongolia has had a close relationship with the Soviet Union (and Russia after the breakup of the Soviet Union). Mongolia even replaced its traditional script with the Cyrillic alphabet. (The traditional script, however, continues to be used by ethnic Mongols in China). As Inner Mongolia was the more populated area before the partition, to this day the number of ethnic Mongols living in China outnumbers the population of Mongolia.
The Secret History of the Mongols is one of the great recordings of Mongolian history. Every Mongolian reads the book in the modern Mongolian language. This is one of the the oldest books in the Mongolian language. There are vivid similarities with the Bible in literary style, wording and storytelling. It is speculated that the author could have been a Christian or at least was very knowledgeable about the Bible. According to Hugh Kemp, Qadag (pp 85-90, Steppe by Step) is the most likely candidate for authorship of Secret History of the Mongols. He writes about the history of ancient Mongolia and connects the modern reality with the ancient world. Even though the book is about the history of Christianity in Mongolia, it paints a view of ancient Mongolia from the height of 21st century. The "History of Mongolia" by B. Baabar is a good source for the Modern History of Mongolia.
On the trail of Marco Polo covers some travel through the Mongol Empire in the time of Genghis' grandson, Kublai Khan.