Shanghai is the largest city by population in China, with a total population of over 23 million in 2010. It is a global city, with influence in commerce, culture, finance, media, fashion, technology, and transport. It is a major financial center and the busiest container port in the world. Located in the Yangtze River Delta in East China. For centuries a major administrative, shipping, and trading town, Shanghai grew in importance in the 19th century due to European recognition of it as a favorable port and its economic potential. The city was one of several opened to foreign trade following the British victory over China in the First Opium War and the subsequent 1842 Treaty of Nanking which allowed the establishment of the Shanghai International Settlement.