lha bug pa can pa'i gdung rabs spyan snga'i 'khrungs rabs bcas/ gives the earth-horse year 1258 Gyalbo & Hazod et al. 2000 (p. 39)
General
"administrative center of the phag mo gu khri skor/ and in the 14th century, under byang chub rgyal mtshan/ [= ta'i si tu byang chub rgyal mtshan/ (1302–1364)], it became the capital of the rlangs phag mo gu pa/ rule" Gyalbo & Hazod et al. 2000 (p. 34 n. 69)