Wu’s Wuchang is modern Ezhou, on the Yangzi. Around 221–229 Sun Quan placed the court here so he could watch Jing, then moved back to Jianye. Wuchang stayed the upriver garrison. Lu Xun’s Jing command sat in this country.
Do not equate it automatically with the later Wuchang inside Wuhan. The name drifted downriver. For Lu Xun and for Sun Quan’s enthronement, the map belongs beside Ezhou, not by default in the modern provincial capital.