 The Taika era innovation of naming time periods – "nengō" – languished until Mommu reasserted an imperial right by proclaiming the commencement of Taihō in 701.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