The Yangtze Delta or Yangtze River Delta (YRD, or simply ) is a triangle-shaped megalopolis generally comprising the Wu Chinese-speaking areas of Shanghai, southern Jiangsu, northern Zhejiang and northern Jiangxi. The area lies in the heart of the Jiangnan region (literally, "south of the River"), where the Yangtze River drains into the East China Sea. Having fertile soil, the Yangtze Delta abundantly produces grain, cotton, hemp and tea. In 2018, the Yangtze Delta had a GDP of approximately US$2.2 trillion, about the same size as Italy. The urban build-up in the area has given rise to what may be the largest concentration of adjacent metropolitan areas in the world. It covers an area of around and is home to over 115 million people as of 2013, of whom an estimated 83 million are urban. If based on the greater Yangtze Delta zone, it has over 140 million people in this region. With about a tenth of China's population and a fifth of the country's GDP, the YRD is one of the fastest growing and richest regions in East Asia measured by purchasing power parity. History Since the fourth century, when the national capital was moved to Jiankang (present-day Nanjing) at the start of the Eastern Jin dynasty (AD 317–420), the Yangtze Delta has been a major cultural, economic, and political centre of China. Hangzhou served as the Chinese capital during the Southern Song dynasty (1127–1279), and Nanjing was the early capital of the Ming dynasty (1368–1644) before the Yongle Emperor moved the capital to Beijing in 1421. Other key cities of the region in pre-modern times include Suzhou and Shaoxing. The ancient Suzhou was the capital of the Wu state (12th century BC–473 BC), and the ancient Shaoxing was the capital of the Yue state (20th century BC?–222 BC). Nanjing first served as a capital in the Three Kingdoms period as the capital of Eastern Wu (AD 229–280). In these periods, there were several concomitant states or empires in China and each one had its own capital. Since the ninth century, the Yangtze Delta has been the most populous area in China, East Asia, and one of the most densely populated areas of the world. During the mid to late period of the Tang dynasty (618-907), the region emerged as an economic centre, and the Yangtze Delta became the most important agricultural, handicraft industrial and economic centre for the late