These murals were removed from Cave #9 in Bezeklik in 1905 by Albert von Le Coq, who identified the figures as Uigurian noblemen and princesses after translating the inscriptions found in the cartouches found in the upper right corners of both mural fragments. On the first fragment, the inscription reads, "Tutuq Bugra, [the house of] Sali," indicating that these three men (or at least the first of the three, as the other cartouches are left blank) were members of the prestigious and powerful Sali family of Khocho. Two inscriptions were included on the second fragment, though only one is still legible. It reads, "Portrait of the Joyful Princess," and since the other female in this fragment is posed and dressed identically, it is likely that she, too, is a Uighur princess.¹

One scholar has noted that in some Uighurian prayers, the deceased are referred to as "those who hold the flowers." This fact, along with corroborating information from texts discovered in Dunhuang, has given rise to the theory that it was a Uigurian custom to show respect for the dead by commissioning a portrait of a deceased relative grasping a flower.²  It appears in these murals that the flowers held by each of these aristocrats were added sometime after the mural was completed (see detailed view), which may indicate that these donor portraits were completed when the family members were alive, with the flowers added after the subjects had passed away.

References:

(1) Doitsu Torufan tankengumi: Sai'iki bijutsuten (Tokyo: Tokyo National Museum, 1991), pp. 158, 159.

(2) Anne-Marie von Gabain, Das Leben in uigurischen Kônigreich von Qoco (850-1250) (Wiesbaden, 1973), p. 165f. Quoted in Along the Ancient Silk Routes (New York: Metropolitan Museum of Art, 1982), p. 169.