King Wen of Zhou
Based upon linguistic and thematic consistencies, modern scholarship reveals that 32 chapters constitute a textual "core" treating governmental and military topics. The remaining 27 "Yizhoushu" chapters are heterogeneous. Some describe historical events ranging from King Wen of Zhou (r. 1099-1050 BCE) down to King Jing of Zhou (Gui) (r. 544-520 BCE); supplementary chapters record topics such as astronomy (52 "Shixun" 時訓) and posthumous names (54 "Shifa" 謚法).