Luoyang is a prefecture-level city in western Henan province of Central China. It borders the provincial capital of Zhengzhou to the east, Nanyang to the south, Sanmenxia to the west, and Jiyuan to the north. During the Tang Dynasty, Luoyang was Dongdu, the "Eastern Capital", and at its height had a population of around one million, second only to Chang'an, which, at the time, was the largest city in the world. During the short-lived Five Dynasties, Luoyang was the capital of the Later Liang, Later Tang, and Later Jin. During the North Song Dynasty, Luoyang was the "Western Capital" and birthplace of Zhao Kuangyin, the founder of Song Dynasty.