This event is set at the end of the Eastern Han dynasty around the time of the Yellow Turban Rebellion in the 180s A.D. Liu Bei, Guan Yu and Zhang Fei took an oath of fraternity in a ceremony in the Peach Garden (believed to be in present-day Zhuozhou, Hebei), and became sworn brothers from then on.

[6] In Records of the Three Kingdoms in Plain Language, Zhang Fei first met Guan Yu in Zhuo County and appreciated his outstanding appearance, so he invited him to a drink.

The three men went to drink together at Zhang Fei's peach garden and swore to become brothers, before Liu Bei expressed his lofty aim to save the nation.

Chapter 1 of Romance of the Three Kingdoms sets out the story of the Ten Attendants' usurpation of power and the Yellow Turban Rebellion, which destabilised the Han Empire.

Liu Bei then shared his aspirations of saving the country and the people, and Zhang Fei suggested they should together recruit a voluntary militia to combat the Yellow Turbans.

Zhang Fei suggested they should conduct a sacrificial ceremony to heaven and earth and take the oath as brothers under blossoming peach trees in his garden, to which Liu Bei and Guan Yu agreed.

The oath, as it appears in the Wikisource translation of Chapter 1 of Romance of the Three Kingdoms, was this: When saying the names Liu Bei, Guan Yu and Zhang Fei, although the surnames are different, yet we have come together as brothers.

Liu Bei ordered the craftsman to forge a pair of swords, Guan Yu the Green Dragon Crescent Blade and Zhang Fei a 1.8-zhang Snake Lance.

When Liu Bei ascended to the throne to restore the house of Han, his first edict was to wage war on Sun Quan to avenge Guan Yu.

"Though not born on the same day of the same month in the same year, we hope to die so"[8]—the phrase the three brothers made during the oath—had also become popular among present-day secret society members.