Liu Song dynasty
In the fifth century, Emperor Wen of the Liu Song dynasty felt that Chen Shou's "Sanguozhi" was too short and not comprehensive enough, so he commissioned Pei Songzhi to annotate the "Sanguozhi". Pei Songzhi completed his assignment in 429. He included new materials he collected through research, and added his personal commentary. Pei Songzhi's annotations increased the length of the "Sanguozhi" to nearly twice its original.