Sejong the Great vs Wu Zetian

Sejong the Great commissioned the development of advanced astronomical instruments, including the armillary sphere and water clock. These tools improved timekeeping and calendar accuracy in Joseon.

Sejong the Great launched military campaigns against the Jurchen tribes in the north, securing the border and establishing the Four Forts and Six Garrisons. This expanded Joseon territory and stabilized the frontier.

King Sejong the Great oversaw the creation of Hangul, the Korean alphabet, to improve literacy among commoners. The script was promulgated in 1446 and remains the writing system of Korea.

Sejong the Great officially promulgated the Hunminjeongeum, the document explaining the new Hangul script. This marked the formal introduction of the alphabet to the Korean people.

Wu Zetian was elevated from concubine to empress consort of Emperor Gaozong of Tang in 655. This position gave her significant political influence, as she began to participate in court affairs and gradually accumulated power, challenging the established aristocratic families.

After Emperor Gaozong's death in 683, Wu Zetian became regent for her son, Emperor Zhongzong. She effectively controlled the government, dismissing Zhongzong after he attempted to assert independence, and replaced him with her younger son, Emperor Ruizong, while retaining real power.

Wu Zetian proclaimed herself emperor, founding the Zhou dynasty and becoming the only female emperor in Chinese history. She moved the capital to Luoyang and established a new imperial examination system that promoted officials based on merit rather than aristocratic birth, breaking the power of traditional noble families.

Wu Zetian ordered military campaigns that reasserted Chinese control over the Western Regions, including the Tarim Basin and parts of modern Xinjiang. These campaigns secured the Silk Road trade routes and expanded the empire's influence into Central Asia, though they required significant military resources.

Wu Zetian elevated Buddhism to a state-supported religion, commissioning the construction of temples and statues, including the Longmen Grottoes' giant Vairocana Buddha. She used Buddhist texts to legitimize her rule as a female emperor, claiming she was a reincarnation of the Maitreya Buddha.

In 705, a coup led by court officials and generals forced Wu Zetian to abdicate in favor of her son, Emperor Zhongzong, restoring the Tang dynasty. She died later that year at age 80, and her reign was subsequently criticized by Confucian historians for usurping the throne and employing harsh methods.