Imperial China has a long-standing, multifaceted, and interesting imperial maritime history. Of particular importance in this context are the commercial dimensions of China’s maritime contacts with the outside world. From approximately the 7th century until Yuan 元 times (1279–1367), China even developed as a commercial maritime power, although its maritime trade was, until the late 11th century, basically dominated by foreign merchants. During the Yuan and early Ming dynasties (1368–1644), China was also a naval power—the attempts of Qubilai Khan (r. 1260–1295) to subdue Japan are well known. But their maritime interests took the Mongols as far as Southeast and South Asia. The early Ming 明 period, under the third Ming Emperor, Yongle 永樂 (r. 1403–1424), is characterized by unforeseen political, military, and commercial maritime expansion. After 1435, following the instructions of the first Ming emperor, Hongwu 洪武 (r. 1368–1398), China officially retreated from the seas and prohibited all private maritime commerce, until internal socioeconomic and financial problems and the great demand of foreigners—after 1500 also including the Europeans—for Chinese products urged the government to “reopen” its borders for trade. The rulers of the last imperial dynasty, the Qing 清 (1644–1911), first concentrated on securing their maritime borders against competing commercial and political interests, then managed a flourishing trade, increasingly also with Europeans, but were finally confronted with the colonialist and imperialistic claims of the Europeans. After the Opium Wars (1839–1842), the maritime commerce and politics of China were more and more controlled by European powers, especially the British.