Final answer:
The Tang dynasty collapsed due to a combination of military setbacks, such as the An Lushan rebellion and the Battle of Talas River, internal revolts, economic changes, reduction in central government control, and the rise of powerful warlords, ultimately crumbling by 906 and giving way to a period of disunity.
Step-by-step explanation:
The collapse of the Tang dynasty can be attributed to several factors. The An Lushan rebellion in 755 was a significant event, leaving the dynasty militarily and economically depleted, with warlords gaining power and causing societal chaos. The Tang defeat at the Battle of Talas River by Turkic and Arab armies further diminished their external strength. In addition to these, internal challenges included revolts in Korea, Yunnan, and Manchuria, which distracted and weakened the state. The equal-field system's collapse, leading to land privatization, changed economic dynamics and reliance shifted to commercial taxes. The central government's power waned while local warlords' influence expanded. By 906, these compounded issues led to the fall of the Tang dynasty, with additional civil wars and loss of control over the territories.
Despite the An Lushan rebellion and subsequent struggles, the Tang Empire still witnessed economic development and cultural achievements. Arts such as calligraphy and landscape painting flourished, and renowned poets like Li Bai and Du Fu emerged. The system of entrance examinations for government officials was established, marking a shift in the elite selection process based primarily on merit, not just aristocratic ties.
However, despite these developments, the dynasty could not withstand the accumulated pressure from continuous rebellions, warlord domination, and a weakened central governance system. Thus, the Tang dynasty's legacy ended, making way for a period of disunity until the rise of the Song dynasty.