For centuries a major administrative, shipping, and trading town, Shanghai grew in importance in the 19th century due to European recognition of its favorable port location and economic potential. The city was one of five opened to foreign trade following the British victory over China in the First Opium War while the subsequent 1842 Treaty of Nanking and 1844 Treaty of Whampoa allowed the establishment of the Shanghai International Settlement and the French Concession. The city then flourished as a center of commerce between east and west, and became the undisputed financial hub of the Asia Pacific in the 1930s.