To participate in the campaign against Dong Zhuo, Sun Jian led an army north to join Yuan Shu, who was part of the coalition.
Yuan Shu appointed Sun Jian as Acting General Who Smashes the Caitiffs (破虜將軍) and Inspector of Yu Province (豫州刺史), and sent him to attack Dong Zhuo at the capital city of Luoyang.
Sun Jian's capture of Luoyang, in ruins, was militarily untenable since the other members of the alliance had no mind to reinforce his position, while they themselves were on the verge of dissolution.
Zhou Yu decided to attack Yangcheng of Yingchuan Commandery (潁川; southeast of present-day Dengfeng, Henan).
When Sun Jian heard of the attack, he sighed and commented:[3] Together we rallied troops of righteousness, with a purpose of saving the nation.
The battle of Yangcheng, being the first moves in the struggle between the two Yuans, marked the beginning of a new stage in the confusion of wars which brought the end of the Han dynasty.