The answer is "Centered on military warfare innovations, they established their empire".
Explanation:
The Mongols were recognized as migratory from of the East Asian plain, in which most of Russia, eastern Europe, Asia was briefly ruled by Mongols. They built up a kingdom under the rule of Genghis Khan by attacking the military equipped and disciplined.
It was very capable of adapting due to various their war under attack. In 1236, the Mongols built the capital city in the Karakorum mostly with aid of the qualified people from its conquered territories transported. It has built walls around with a townsite and a palace.
