The Swearing of Brotherhood in the Peach Garden

One day, Liu Bei, Guan Yu and Zhang Fei, coincidentally met on a street. Because of the similarity in their ideals and temper, they made an oath to become sworn brothers.

"We three, Liu Pei, Guan Yu and Zhang Fei, though of different families, swear brotherhood, and promise mutual help to one end. We will rescue each other in difficulty, we will aid each other in danger. We swear to serve the state and save the people. We ask not the same day of birth but we seek to die together. May Heaven, the all-ruling, and Earth, the all-producing, read our hearts, and if we turn aside from righteousness or forget kindliness may Heaven and man spite us!"

--Peach Garden Oath, Romance of Three Kingdoms

Above oath translation courtesy of RTKweb.com