As a project sponsored by Zhang Yichao, the first governor of the Gui-yi-jun regime, and as a milestone of construction following the Tibetan occupation, Mogao cave 156 is representative of a type of Dunhuang cave and holds significant research value. Based on the inscriptions of the donor figures and the stele with the Records about the Construction of the Mogao Grottoes on it, the opinions of academics differ regarding construction date and main donors. It is generally considered to have been constructed between the 5 th or 6 th year of the Dazhong era and the 6 th year of the Xiantong era, though the antechamber and the corridor were completed later by Zhang Huaishen. Some scholars believe it was finished in the 12 th year of the Dazhong era. A careful examination of related historical material about the Gui-yi-jun and a re-study of the way in which the inscription was written suggest that Zhang Huaishen did not participate in the construction of this cave and that it was actually finished between the 5 th and 10 th years of the Dazhong era under the supervision of Zhang Yichao.
