The Emperor Guangwu of Han (15 January 5 BC – 29 March AD 57), born Liu Xiu (Chinese: 劉秀; pinyin: Liú Xiù), courtesy name Wenshu, was a Chinese monarch. He served as an emperor of the Han dynasty by restoring the dynasty in AD 25, thus founding the Eastern Han (Later Han) dynasty. He ruled over parts of China at first, and through suppression and conquest of regional warlords, the whole of China proper was consolidated by the time of his death in AD 57.

Liu Xiu was one of the many descendants of the Han imperial family. Following the usurpation of the Han throne by Wang Mang and the ensuing civil war during the disintegration of Wang's short-lived Xin dynasty, he emerged as one of several descendants of the fallen dynasty claiming the imperial throne. After assembling forces and proclaiming himself emperor in the face of competitors, he was able to defeat his rivals, destroy the peasant army of the Chimei, known for their disorganization and marauding, and finally reunify China in AD 36.

He established his capital in Luoyang, 335 kilometers (208 mi) east of the former capital Chang'an, ushering in the Eastern Han (Later Han) dynasty. He implemented some reforms (notably land reform, albeit not very successfully) aimed at correcting some of the structural imbalances responsible for the downfall of the Former/Western Han. His reforms gave a new 200-year lease of life to the Han Dynasty.

Emperor Guangwu's campaigns featured many able generals, but curiously, he lacked major strategists. That may very well be because he himself appeared to be a brilliant strategist; he often instructed his generals on strategy from afar, and his predictions generally would be accurate. This was often emulated by later emperors who fancied themselves great strategists but who actually lacked Emperor Guangwu's brilliance—usually to great disastrous results.

Also unique among emperors in Chinese history was Emperor Guangwu's combination of decisiveness and mercy. He often sought out peaceful means rather than bellicose means of putting areas under his control. He was, in particular, one rare example of a founding emperor of a dynasty who did not kill, out of jealousy or paranoia, any of the generals or officials who contributed to his victories after his rule were secure.