The Northern Song Dynasty (960-1127) had four capitals, with Kaifeng as the official capital (eastern capital), Henan (present-day Luoyang, Henan province) as the western capital, Yingtian (present-day Shangqiu, Henan province) as the southern capital, and Daming (present-day Daming, Hebei province) as the northern capital. All four capitals were located at hubs of water transportation. In particular, the eastern capital, situated at a tribute grain transportation hub along the Bian River, served as the empire's political, economic and cultural center. Over more than 100 years of construction, Kaifeng, the eastern capital, emerged as the largest and most prosperous city in China and even across the whole world from the 11th century to the early 12th century.