Over more than a century, many editions and translations of Old Turkic inscriptions have been published in different languages.Footnote ¹ However, most of the editors involved have been philologists or linguists. As a result, generally speaking, historical research on Old Turkic inscriptions is less than satisfying. On the one hand, scholars in this field have not made full use of Chinese sources, even though there is already a collection of Chinese materials published in German.Footnote ² On the other hand, our knowledge of Old Turkic inscriptions remains in the field of philology and literature, while questions concerning the structure, authorship and background of the Old Turkic inscriptions have rarely been discussed before. For example, why was an almost identical text inscribed both on the Kül Tégin Inscription and the Bilge Kağan Inscription? When were they inscribed, and by whom? Previous scholars have taken the answers to these questions for granted. This paper is going to apply both the Chinese accounts and the Old Turkic inscriptions to the discussion of the authorship issue.

We know that all four sides plus two edges of the Kül Tégin memorial were inscribed with text. There are 40 lines on the east side, 13 on the north side and 13 on the south side, plus two lines on the edges that were inscribed with Old Turkic text. The west side was inscribed with a Chinese text and one line of Old Turkic text. This extra line of Old Turkic text was obviously added to the Chinese text at a later time. Since the decipherment of the Old Turkic inscriptions, scholars have not reached a consensus on which side constitutes the beginning of the Old Turkic text. For example, W. Radloff and V. Thomsen regarded the east side as the beginning.Footnote ³ However, on the contrary, T. Tekin took the south side as the beginning.Footnote ⁴ After a careful analysis of the Old Turkic text and a comparison of the Chinese accounts concerning the Türk imperial lineage after Bilge Kağan, we come to the conclusion that the south side of the Kül Tégin Inscription is an independent text from the east side.

The east side and north side plus the two edges of the Kül Tégin Inscription consist of a complete inscription. The text starts from the east side. Lines 1-4 talk about the rise and the heyday of the first Türk Empire. Lines 5-7 talk about the crisis in the Türk Empire. Because of the crisis, it had become subordinate to Tang China. Line 8 mentions that the Türks served the Chinese government for 50 years. Lines 9-10 talk about the Türks’ rebellion against Tang China. However, they failed and surrendered again to China. Lines 11-14 talk about the successful rebellion led by Kutluğ, the later Élteriş Kağan. Under the leadership of Élteriş Kağan, the Türk Empire revived. Line 15 talks about the military achievements of Élteriş Kağan. Line 16 talks about the death of Élteriş Kağan and the enthronement of Kapğan Kağan. Lines 17-21 talk about the military career of Kapğan Kağan, especially his campaigns against the Türgiş, On Ok and Kırkız. Lines 22-24 talk about the death of Kapğan Kağan. The Türk officials and common people are accused of having been disloyal to Kapğan Kağan. Lines 25-28 talk about the enthronement of Bilge Kağan. Together with his younger brother Kül Tégin, Bilge Kağan managed to deal with the political chaos within the empire. Lines 29-30 mention that the Türk Empire went through a political crisis.

Starting from line 30, the inscription comes to the biography of the deceased Kül Tégin. The story begins when he lost his father at the age of seven. Lines 31-32 mention that at the age of 16 Kül Tégin joined his uncle's campaign against the Sogdians in Altı Çub (i.e. Six Prefectures). Lines 32-34 talk about his participation in the battle of Beş Balık when he was 21 years old. Line 34 talks about the victory over the Bayırku. Lines 34-40 talk about the campaign against the Kırkız when he was twenty-six years old. Afterwards, the Türk army crossed the Altay Mountains and advanced as far as the Iron Gate.

The text then continues on the north side. Line 1 talks about the rebellion of the Karluks when Kül Tégin was 27 years old. Line 2 talks about the Türk campaign against the Karluks when Kül Tégin was 31 years old. Lines 2-9 talk about the war between the Türks and the Oğuz. Kül Tégin was very brave on the battlefield. In the following year, the Türks campaigned for a second time against the Oğuz people, while Kül Tégin stayed at home to protect women and children. Lines 10-11 talk about the death of Kül Tégin. Lines 12-13 mention that many international representatives came to express their condolences. Line 13 talks about the construction of a memorial and a shrine by the Chinese craftsmen led by General Zhang. The text on the northeast edge offers us the dates of his death and funeral. Finally, on the southeast edge is the information concerning the scribe Yolluğ Tégin.

The text up to here constitutes a complete eulogy for Kül Tégin. It was narrated by his elder brother Bilge Kağan and written down by his cousin Yolluğ Tégin. The Chinese craftsmen helped them inscribe the text onto the marble. The whole construction was finished on the 25th day of the 7th month of the monkey year (22 Aug. 732).

What about the south side of the Kül Tégin inscription? For further discussion, we will first cite the translation of the original text.

Who was the author of the south side of the Kül Tégin inscription? Previous scholars have never asked the question of authorship. They thought that it was self-evidently Bilge Kağan.Footnote ⁶ However, there are at least four counter arguments to the idea that the text on the south side of the Kül Tégin Inscription was composed by Bilge Kağan on the occasion of Kül Tégin's funeral.

1. (1) The first sentence on the south side of the Kül Tégin inscription is: teŋri teg teŋride bolmış türk bilge kağan bu ödke olurtum, which can be translated as “I, Teŋri Teg Teŋride Bolmış Türk Bilge Kağan (lit. the heaven-like, created in/from heaven, wise Türk kağan), have ascended the throne at this moment”. There are two questionable points in this sentence. First, the kağan title here is much longer and more complicated than that of Bilge Kağan. Before Bilge Kağan, the Türk kağan titles were very short, e.g. Élteriş Kağan, Kapğan Kağan and Bilge Kağan. The practice of adding attributive components to the kağan titles in the Türk Empire was probably started by Bilge Kağan's successor. Second, Bilge Kağan ascended the throne in the year 716, 17 years before the establishment of Kül Tégin's memorial in 732. The statement that “I have ascended the throne at this moment” was no way spoken by Bilge Kağan at the occasion of the construction of the Kül Tégin memorial.

2. (2) The campaign itinerary described here does not agree with the itinerary described by Bilge Kağan on the east side. K. S. 3-4: “I campaigned eastwards as far as Shandong Plain and almost reached the sea. I campaigned southwards, as far as Tokuz Ersin and almost reached Tibet. I campaigned westwards, crossing the Yinçü River, and as far as Iron Gate. I campaigned northwards, as far as the land of the Bayırku.” K. E. 17: “Together with my uncle, the kağan, we campaigned eastwards as far as the Yellow River and Shandong Plain, westwards as far as the Iron Gate, [northwards] across Kögmen Mountain as far as the land of the Kırkız.”

   It is not difficult to notice that apart from the western campaign towards the Iron Gate and the eastern campaign towards Shandong, the campaigns in the other two directions are totally different. The latter itinerary does not even mention any campaign in the south. In fact, the western campaign towards the Iron Gate and the eastern campaign towards Shandong were two regular campaigns of the Türk kağans. Before Bilge Kağan (including himself), every kağan had made such two campaigns.Footnote ⁷ If both of the narratives were by Bilge Kağan, we should ask two questions: What was the necessity for him to describe his campaign itinerary twice on the same stone? Why were the two narratives different from each other?

3. (3) The basic tone of the text on the south side is threatening. The narrator spoke to his audience with an arrogant air. His audience included Türk officials, common people, and even the On Ok people. As his subjects planned to move to Chinese territory, he warned them of the Chinese people's trickery and cunning, pointing out that their fine treasures and sweet promises were only sugar-coating reality. Obviously, the crisis situation described here does not agree with the actual situation of Bilge Kağan's reign. After 18 years’ peaceful relationship with the Tang government, the Türks had grown to be very strong and united under the leadership of Bilge Kağan. Türk officials and common people had no reason to escape from their homeland.

   Rather, the severe situation described here looks more like what was happening at the end of the second Türk Empire. Moreover, the anti-China sentiment expressed in this text contradicts the pro-China posture of Bilge Kağan, who maintained peaceful relations with the Tang government during his 19-year-long reign.Footnote ⁸ Besides the campaign against the Kıtañ and Tatabı in Kaiyuan XXI (ca. 733), which happened one year after the construction of Kül Tégin's memorial, there was only one small clash between the Türks and Tang during his reign.Footnote ⁹ Bilge Kağan also persisted in pursuing a Türk-Tang marriage alliance through his friendly gestures.Footnote ¹⁰

4. (4) The whole text does not mention a single word about Kül Tégin, which indicates that it has nothing to do with Kül Tégin and could not have been composed upon the occasion of his death or funeral.

Considering the above four counter arguments, we would argue that it is necessary to abandon the traditional theory and to look instead for a new solution. A slightly different text was inscribed on the north side of the Bilge Kağan memorial. Moreover, the background of the east side and south side of the Bilge Kağan inscription is very clear. According to his inscription, Bilge Kağan passed away on the 26^th day of the 10^th month of the dog year; and his funeral was held on the 27^th day of the 5^th month of the pig year.Footnote ¹¹ However, his epic autobiography does not mention the cause of his death.

Chinese sources tell us that he was poisoned by his minister Buyruk Çor. The reason why Buyruk Çor attempted to murder Bilge Kağan is unclear. But Bilge Kağan did not die instantly after being poisoned. Having recognised the conspiracy, he took some emergency actions. Bilge Kağan executed Buyruk Çor and other members of the latter's clan. Unfortunately, sometime later, the poison in his body began to show effect and eventually took his life. The news of Bilge Kağan's death arrived at the Tang court on the 23^rd day of the 12^th month (21 January 735). The Tang emperor ceased court meetings for three days, expressing his condolences for Bilge Kağan. He composed an edict, in which he spoke highly of Bilge Kağan's friendly policy towards the Tang. Four days later, the Tang court held a funeral ceremony for Bilge Kağan at the south gate of Luoyang. General Li Quan attended the ceremony and expressed his condolences.Footnote ¹² According to the information on the Bilge Kağan inscription, his official funeral was held on the 27^th day of the 10^th month of the pig year (Kaiyuan XXIII). The Chinese emperor sent Li Quan to Türk to attend the funeral.Footnote ¹³

There is still one thing that must have been done by Bilge Kağan in his last few hours or days in the world. We are not sure how long he did survive after being poisoned, but since he still had enough energy to execute Buyruk Çor and his entire clan, this leads us to believe that he also had the energy to finish his autobiographical narrative before he died. If we make a comparison between the Kül Tégin inscription and the Bilge Kağan inscription, we can see how Bilge Kağan re-edited his earlier narrative, which had been prepared for his younger brother two years earlier.

Bilge Kağan borrowed the passages concerning his forefathers, father and uncle from his previous composition, making only a few minor changes. But he replaced the biographical description of his younger brother with his own autobiography, which means that he changed the narrative pronoun from the third person singular ‘he’ to the first person singular ‘I’, as the two brothers had been involved in most of the campaigns together. There are also a few other campaigns narrated only in the Kül Tégin inscription, and vice versa. Hence, the two inscriptions supplement each other and offer us an almost complete chronology of Bilge Kağan's reign.

The opening sentence of the east side of Bilge Kağan Inscription reads as follows: “These words are mine, i.e. Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan. My father, the Türk Bilge Kağan… Having ascended the throne…” It directly tells us that Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan was the son and successor of Bilge Kağan. The content from the second half of line 2 to the first half of line 10 on the south side is the narrative of Bilge Kağan. The rest of the inscription (lines 10-15, the southwest edge and 1 line on the west side) concerns Bilge Kağan's funeral, of course also narrated by his son and successor, Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan. In other words, the establishment of Bilge Kağan's memorial was organised by his son and successor Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan, who simply inserted an introduction about his own enthronement and an ending concerning the funeral, while the main body of the eulogy was made up of the autobiographical text left by his father.Footnote ¹⁴

The successful identification of Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan can help us solve the authorship of the north side of the Bilge Kağan inscription and the south side of the Kül Tégin inscription. The first sentence of the text in question is “I, Teŋri Teg Teŋride Bolmış Türk Bilge Kağan, have ascended the throne at this moment”. The subject is a complicated kağan title. As we have discussed above, the phenomenon of having complicated kağan titles appeared after Bilge Kağan. This title is similar to “Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan”, but the difference lies in the middle as teŋri Yaratmış means “created by heaven” while teŋride bolmış means “born in heaven”. If the former was the successor of Bilge Kağan, who could the latter be? We have to look at the Chinese accounts for an answer.

Chinese accounts concerning the imperial lineage after Bilge Kağan are ‘contradictory’. On the one hand, Jiu Tangshu (hereafter JTS) and Xin Tangshu (hereafter XTS) say that after Bilge Kağan's death the new Türk kağan was Yiran (EMC: ʔji-ɲian).Footnote ¹⁵ On the other hand, in the letters of Zhang Jiuling addressed to the Türk kağan and in the Chinese text of the Bilge Kağan inscription his name is written as Dengli (EMC: təŋ-li^h < OT: teŋri).Footnote ¹⁶ As to the length of the reign of Bilge Kağan's successor, there are also contradictory reports in the Chinese sources. According to JTS, after his enthronement, “later, Yiran died of sickness, and his younger brother Dengli ascended the throne”. In Kaiyuan XXVIII, the Chinese envoy Li Zhi was sent to “appoint” Dengli Kağan.Footnote ¹⁷ However, XTS offers us a slightly different version of the story. It says that Yiran stayed on the throne for eight years and then died. His younger brother was appointed by the Chinese envoy as Dengli Kağan.Footnote ¹⁸

Previous scholars have attempted to explain this contradiction. For example, Paul Pelliot proposed two solutions. One solution is that Yiran was the successor of Bilge Kağan, but when the Chinese envoy arrived, he had already passed away and his brother Dengli had ascended the throne. The other solution is that Yiran was the successor of Bilge Kağan and he himself later changed his title to Dengli.Footnote ¹⁹ Cen Zhongmian rejected Pelliot's first proposal and agreed with his second that Yiran and Dengli were the same person.Footnote ²⁰ Xue Zongzhen also followed the second proposal of P. Pelliot but he made some modifications. Xue pointed out that Yiran and Dengli are transcriptions of different parts of the same title: teŋri yaratmış bilge kağan.Footnote ²¹ However, Pelliot's second proposal obviously contradicts the report in XTS and JTS that, after the death of Yiran Kağan, his younger brother Dengli Kağan ascended the throne, which means Yiran and his younger brother Dengli should be recognised as two different people.Footnote ²²

As we have discussed above, the east side of the Bilge Kağan inscription clearly indicates that Bilge Kağan's successor was Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan. Our solution to the conflicting accounts in the Chinese sources is that there were two Dengli kağans after Bilge Kağan (the elder ascended the throne in Kaiyuan XXII while the younger ascended the throne in Kaiyuan XXVIII), and the Chinese accounts saying that Yiran and Dengli were the successors of Bilge Kağan are both correct, as they are in fact two different transcriptions of the title of the first Dengli Kağan, Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan. More exactly, yiran was a transcription of yaratmış, and dengli was a transcription of teŋri. Meanwhile, yiran was an abbreviated form, corresponding to yarat- “to make”, the suffix -mış was not transcribed. Therefore, the records in the Chinese sources concerning the identity of Bilge Kağan's successor are actually not contradictory.

As to how long Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan stayed on the throne, this is not difficult to answer. According to XTS, he ascended the throne in Kaiyuan XXII (ca. 734) and ruled for eight years. XTS also informs us that his successor was acknowledged and legitimised by the Tang envoy in Kaiyuan XXVIII (ca. 740), indicating that he died in this year.Footnote ²³ However, from Kaiyuan XXII to Kaiyuan XXVIII there are only seven years, if we count in the Chinese way.Footnote ²⁴ This mistake by the author of XTS should be regarded merely as carelessness. On the contrary, the information in JTS is much more ambiguous: “Yiran ascended the throne. Later, he died of sickness”.Footnote ²⁵ We cannot figure out how long “later” was. So, here we follow the record of XTS, except for the arithmetic error, which means Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan reigned over the Türks for seven years from ca. 734 to ca. 740.

The reason why many scholars were confused by the Chinese accounts on the Türk imperial lineage after Bilge Kağan is that in Kaiyuan XXVIII the successor and younger brother of Dengli Kağan/Yiran Kağan was also called Dengli Kağan. If the Dengli Kağan who ascended the throne in Kaiyuan XXII was Bilge Kağan's son and successor Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan, then who can the other Dengli Kağan be? It must be the so-called Teŋri Teg Teŋride Bolmış Türk Bilge Kağan mentioned on the south side of the Kül Tégin inscription and on the north side of the Bilge Kağan inscription. Obviously, dengli was a transcription of the first attributive part of his title (i.e. teŋri). In other words, the author of the south side of the Kül Tégin inscription was Teŋri Teg Teŋride Bolmış Türk Bilge Kağan, who was one of Bilge Kağan's sons. He ascended the throne in Kaiyuan XXVIII (ca. 740). He is recorded in the Chinese sources as Dengli Kehan (< teŋri kağan).

In his narrative, Teŋri Teg Teŋride Bolmış Türk Bilge Kağan first addressed his listeners and declared his authority over a large territory.Footnote ²⁶ Then he talked about the military campaigns that he had joined and the places that he had reached, and came to the conclusion that Ötüken was the best place in the world.Footnote ²⁷ He must have accompanied his elder brother in these campaigns, because his own reign lasted for only one year. He went on to remind his people of the Chinese being tricky and deceitful and to try to persuade them not to leave Ötüken for China. He emphasised the potential benefits for his subjects if they stayed in Ötüken.Footnote ²⁸ In the end, he threatened his people and ordered the craftsmen to carve his words upon the everlasting stone, so as to let his people read and comprehend them.Footnote ²⁹

The image given by Teŋri Teg Teŋride Bolmış Türk Bilge Kağan's narrative agrees perfectly with the situation in the Türk Empire after his enthronement. From the Chinese sources we know that he faced many challenges both internally and externally. Externally, he faced a challenge from the Tokuz Oğuz tribes, who were ready to replace the Türks’ dominant status on the steppe. Internally, he lost control of the army. His two uncles, the Right Şad and the Left Şad, both had a considerable number of well-equipped troops in their hands.

In order to decrease his two uncles’ military influence and retake power over the army, he made a plan with his mother. They decided to deal with the Right Şad first, managing to kill him and absorb his military forces. However, before they carried out the next step of their plan, the Left Şad realised what they were doing and preempted them. The newly enthroned kağan was killed by his uncle in the second year of his reign.Footnote ³⁰ The news of his death arrived at the Tang court on the 18th day of the 7th month of Kaiyuan XXIX (2 September 741).Footnote ³¹ If we take into consideration the two months spent on the way, Teŋri Teg Teŋride Bolmış Türk Bilge Kağan is likely to have passed away in June 741.Footnote ³² The purpose of Teŋri Teg Teŋride Bolmış Türk Bilge Kağan in inscribing such a text was, of course, to persuade the Türk people not to leave their country. He wanted to stop or at least to slow down the decline of his empire.

The text of lines 1-8 and 14-15 on the north side of the Bilge Kağan inscription is almost the same as that of the south side of the Kül Tégin inscription. Therefore, the author should also be Teŋri Teg Teŋride Bolmış Türk Bilge Kağan. However, there are a few lines (i.e. lines 9-14) that cannot be found on the south side of the Kül Tégin inscription:

Judging by the context, the words of lines 9-12 cannot have been spoken by Teŋri Teg Teŋride Bolmış Türk Bilge Kağan. Instead, we must assume that these words are a direct quotation from his father Bilge Kağan.Footnote ³³ The form of address, i.e. “my father, the kağan” and “my uncle, the kağan”, can help us identify the speaker as Bilge Kağan, because among the rulers of the second Türk Empire, only he had both a father kağan and an uncle kağan.Footnote ³⁴ Moreover, the formulation of “I caused the people who had heads to bow down and the people who had knees to kneel down” appear several times in the autobiographical narrative of Bilge Kağan.Footnote ³⁵ As to the marriage relation with the Türgiş kağan, we can also find supporting evidence in the Chinese sources and Old Turkic inscriptions.Footnote ³⁶ From line 12, more exactly after the formulation of “Mighty heaven above”, Teŋri Teg Teŋride Bolmış Türk Bilge Kağan returns to his own crisis situation. He attempts to persuade his people not to leave their country.

At the end of his narrative, Teŋri Teg Teŋride Bolmış Türk Bilge Kağan mentions that he asked the Chinese craftsmen to build a gorgeous shrine and establish an inscription. According to the Chinese sources, in Kaiyuan XXVIII, when Yiran/Dengli Kağan (Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan) passed away, the Chinese emperor dispatched General Li Zhi to ‘appoint’ the new Dengli Kağan (Teŋri Teg Teŋride Bolmış Türk Bilge Kağan).Footnote ³⁷ It does not mention the construction of an inscription or a shrine. Teŋri Teg Teŋride Bolmış Türk Bilge Kağan must have taken the opportunity of the visit of the Chinese delegates and asked them to carve his words onto the stones. The text of his inscription commemorates not his brother but his father, i.e. Bilge Kağan. That can also explain why it was carved on Bilge Kağan's memorial, and why he inserted a quotation of his father's words (lines 9-12). Almost at the same time, a shorter edition of the same text was inscribed on Kül Tégin's memorial. The Türk scribe of the text is still Bilge Kağan's (also Kül Tégin's) nephew Yolluğ Tégin.

It is noteworthy that in the text concerning Bilge Kağan's funeral in 735, Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan does not mention the construction of a shrine and stele.Footnote ³⁸ The Chinese accounts on the other hand say that the Chinese craftsmen built an inscription and shrine.Footnote ³⁹ However, the Chinese accounts do not mention whether the craftsmen painted on the sides of Bilge Kağan's shrine. Considering the fact that Bilge Kağan's tomb is much larger in scale and much richer in treasures than Kül Tégin's, it is reasonable for us to assume that Teŋri Teg Teŋride Bolmış Türk Bilge Kağan might have repaired his father's imperial tomb in the year Kaiyuan XXVIII (ca. 740), and had his words inscribed onto his father's (and also his uncle's) stele. If so, the report that he asked the Chinese craftsmen to build a gorgeous shrine and decorate the interior and exterior of the shrine could be well explained.

Let us now sum up the main points of the above discussion. The successor of Bilge Kağan was his elder son: Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan, whose title appears at the beginning of his father's memorial because he was the organiser of the memorial's establishment.Footnote ⁴⁰ The title of Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan was transcribed into Chinese in two different ways: Yiran and Dengli. The two variant Chinese terms were transcribed from the two different parts of his Turkic title, from teŋri and Yaratmış respectively. Teŋri Teg Teŋri Yaratmış Türk Bilge Kağan ascended the throne in Kaiyuan XXII (ca. 734), and his reign lasted for seven years, until Kaiyuan XXVIII (ca. 740), if we count in the traditional Chinese way. After his death, his younger brother ascended the throne, and his title is also recorded in the Chinese sources as Dengli Kağan. The younger Dengli Kağan corresponds to the Teŋri Teg Teŋride Bolmış Türk Bilge Kağan on the south side of the Kül Tégin inscription and the north side of the Bilge Kağan inscription.

To conclude, the author of the south side of the Kül Tégin inscription was Bilge Kağan's younger son Teŋri Teg Teŋride Bolmış Türk Bilge Kağan. Likewise, he was also the author of the north side of the Bilge Kağan inscription, except for a brief quotation of his father's words. He must have taken the opportunity of the visit of the Chinese craftsmen in Kaiyuan XXVIII (ca. 740) and asked them to inscribe his words onto his father's memorial.