Otto I the Great vs Wu Zetian

Otto married Adelaide, the widowed queen of Italy, after intervening in Italian politics. This marriage gave him control over the Kingdom of Italy and strengthened his claim to imperial authority.

Otto led a German army to defeat the Magyar (Hungarian) forces at the Lechfeld near Augsburg. This victory ended Magyar raids into Western Europe and secured Otto's reputation as a defender of Christendom.

Pope John XII crowned Otto I as Holy Roman Emperor in Rome, reviving the imperial title in the West. This event established the Holy Roman Empire as a major political entity and linked German kingship with papal authority.

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.