As Xiao Kui's older brother and Emperor Xuan's original heir apparent Xiao Liao (蕭嶚) had died earlier, Emperor Xuan created Xiao Kui crown prince. Emperor Xuan was, however, never able to gain much support among Liang's provinces and was only able to hold a small amount of territory around his capital Jiangling (江陵, in modern Jingzhou, Hubei).
The succession of Xiao Kui to the throne was influenced by the death of Xiao Liao, who had been Emperor Xuan's original heir apparent.  Emperor Xuan's limited control over Liang's provinces and his restricted territory around Jiangling were a consequence of this situation.