1. The British Empire: The British had a significant presence in China from the early 19th century onwards. They engaged in trade and established economic and political dominance, particularly through the Treaty of Nanking in 1842, which gave them control over Hong Kong and opened five Chinese ports to foreign trade.
2. The French Empire: The French had a strong interest in China during the 19th century. They were involved in military campaigns and established spheres of influence in the regions of present-day Vietnam, Cambodia, and Laos.
3. The Russian Empire: Russia expanded into Central Asia and had territorial disputes with China over areas like Xinjiang and Mongolia. The Treaty of Aigun in 1858 and the Treaty of Peking in 1860 resulted in the cession of large territories from China to Russia.
4. The United States: While not traditionally considered an imperial power in China, the United States played a significant role in shaping China's modern history. The Open Door Policy, which sought to maintain equal trading opportunities for all nations in China, and later the involvement of the United States in the Chinese Civil War and the Korean War, had major impacts on China's political and economic development.
It's important to note that imperialism in China was a complex and multifaceted process involving multiple powers, and the influence and impact of each varied over time.