The Sui Dynasty (589-618 CE) was a short-lived Imperial Chinese dynasty. Preceded by the Southern and Northern Dynasties, it unified China for the first time after nearly four centuries of north-south division. It was followed by the Tang Dynasty.

Founded by Emperor Wen of Sui, the Sui Dynasty capital was at Chang'an (which was renamed Daxing). His reign saw the reunification of Southern and Northern China and the construction of the Grand Canal. Emperors Wen and Yang undertook various reforms including the Equal-field system, which was initiated to reduce the rich-poor social gap that resulted in enhanced agricultural productivity, as well as government centralisation and reforms, creating a new model of governance after centuries of division. The Three Departments and Six Ministries system was officially instituted, coinage was standardized and re-unified, defense was improved and the Great Wall expanded. Buddhism was also spread and encouraged throughout the empire, uniting the varied peoples and cultures of China.

Guan Yu (died 219) was a general serving under the warlord Liu Bei during the late Eastern Han Dynasty of China. He played a significant role in the civil war that led to the collapse of the Han Dynasty and the establishment of the state of Shu Han during the Three Kingdoms period, of which Liu Bei was the first emperor.

As one of the best known Chinese historical figures throughout East Asia, Guan's true life stories have largely given way to fictionalized ones, mostly found in the historical novel Romance of the Three Kingdoms or passed down the generations, in which his deeds and moral qualities have been lionized. Guan is respected as an epitome of loyalty and righteousness.

Guan was deified as early as the Sui Dynasty and is still worshipped by many Chinese people today, especially in southern China, Taiwan, and Hong Kong and their descendants overseas. He is a figure in Chinese folk religion, popular Confucianism, Taoism, and Chinese Buddhism, and small shrines to Guan are almost ubiquitous in traditional Chinese shops and restaurants.