 The years of Kōgyoku's reign are not linked by scholars to any era or "nengō".The Taika era innovation of naming time periods – "nengō" – was yet to be initiated during her son's too-brief reign.In this context, Brown and Ishida's translation of "Gukanshō" offers an explanation about the years of Empress Jitō's reign which muddies a sense of easy clarity in the pre-Taiho time-frame