What major internal upheaval significantly weakened the Tang dynasty?

• A. An Lushan Rebellion
• B. Huang Chao Rebellion
• C. Taiping Rebellion
• D. Yellow Turban Rebellion

Answer: (A)

A massive internal rebellion weakened the Tang dynasty by crippling the central authority and shifting real power to regional military leaders. This upheaval began in 755 when a trusted general, An Lushan, rose in rebellion and rapidly overran northern China, even threatening the capital. The fighting dragged on for years, causing enormous destruction, loss of life, and crippling fiscal resources. In the aftermath, the Tang court had to rely more on powerful provincial generals (the jiedushi), who operated with increasing autonomy. That rise of regional military power undercut centralized control and made the dynasty fragile for the remainder of its existence.

The other events listed are from different times: one occurred later in the Tang period but after An Lushan and intensified decline; another happened in the Qing era, and the last in the Han era.