The Turkic languages and dialects are spoken across a vast area from Eastern Europe and the Mediterranean to Siberia and Western China. The Orkhon Turks are the first nomadic people in present Mongolia who left their own written records down to us. These records are the inscriptions found in present-day Outer Mongolia, mainly in the basin of the Orkhon River, thus being conveniently called ‘the Orkhon inscriptions’. These are the Kül Tegin, Bilgä Kagan, Tuñukuk, Išbara Tarkan (Ongi), and Küli Čor (Ikhe-Khüshötü) inscriptions.
Since the well-known Danish scholar Vilhelm Thomsen succeeded in deciphering the Old Turkic script used in the Orkhon and Yenisei inscriptions of the ancient Turks, many researchers tried to interpret the texts of the inscriptions. Most parts of the inscriptions are already well read.
Many parts of the Kül Tegin (= KT) and Bilgä Kagan (= BK) inscriptions are almost identical. The letter group of B²ẄK²L²I is found once in KT E 4 and BK E 5 and once again in KT E 8 and BK E 8. The Japanese scholar Iwasa Seiichirō had already read B²ẄK²L²I as bökli 貊句麗 ‘句麗 of the 貊 mäk people’. It is also possible to read B²ẄK²L²I as bökküli or bökköli. The name bökküli or bökköli can be analyzed as bökküli (< *bäkküli < *mäkküli 貊句麗) or bökköli (< *bäkköli < *mäkkoli 貊高麗).
This letter group of B²ẄK²L²I has been usually treated together with the next letter group of ČẄL²G²L² (or ČẄL²G²IL²). However, none of the readings and translations so far of B²ẄK²L²I together with ČẄL²G²L² (or ČẄL²G²IL²) are satisfactory. Moreover, all of the researchers overlooked that there were two Tabgač states in northern China in 552 ~ 577, i.e. in the first 25 years of the Turkic Kaganate. In all probability, ČẄlgl (or ČẄlgIl) and Tabgač are the Northern Zhou and the Northern Qi, respectively.
Now, the letter groups B²ẄK²L²I : ČẄL²G²L² (or ČẄL²G²IL²) : T¹B¹G¹Č in this passage should be read as Bökküli (or Bökköli), Čülüg el, Tabgač “Bökküli (or Bökköli = Goguryeo), Čülüg el (= the Northern Zhou), Tabgač (= the Northern Qi)”

1 정재훈, "위구르 유목제국사 744~840" 2005

2 김병호, "오르혼 옛 튀르크語 비문과 한반도인의 옛 이름- 퀼 테긴 碑와 빌게 카간 碑에 나타나는 ‘Bökli’ 해석" 동북아역사재단 (42) : 7-45, 2013

3 탈랴트 테킨, "돌궐어 문법" 한국학술정보 2012

4 정재훈, "돌궐 유목제국사 552~745" 2016

5 Sertkaya, Osman Fikri, "돌궐 비문들에 있는 한국의 이름" 33-48, 2015

6 Tekin, Talat, "돌궐 비문 연구 — 퀼 티긴 비문, 빌개 카간 비문, 투뉴쿠크비문 —" 2008

7 노태돈, "고구려의 대외관계와 북아시아 유목민 국가" 동양학연구원 (58) : 193-202, 2015

8 Bang, Willy, "Zu den Kök Türk-Inschriften der Mongolei" 7 (7): 325-355, 1896

9 Li, Yong-Sŏng, "Zu QWRDNTA in der Tuńuquq-Inschrift" 47 (47): 229-241, 2003

10 Radloff, Wilhelm, "Versuch eines Wörterbuchs der Türk-Dialecte IV" 1911

11 Radloff, Wilhelm, "Versuch eines Wörterbuchs der Türk-Dialecte III" 1905

12 Çagatay, Saadet Ş., "Türk Lehçeleri Örnekleri: VIII. yüzyıldan XVIII. yüzyıla kadar Yazı Dili [튀르크 방언들의 예들: 8 세기부터 18 세기까지문어]" 62 : 1950

13 Grousset, René, "The Empire of the Steppes: A History of Central Asia" 1970

14 Berta, Árpád, "Sözlerimi İyi Dinleyin… [나의 말들을 잘 들으시오…], Türk ve Uygur Runik Yazıtlarının Karşılaştırmalı Yayını [튀르크 및 위구르 룬비문들의 대조 출판]" 1008 : 2010

15 Berta, Árpád, "Szavaimat jól halljátok…, A Türk és Ujgur rovásírásos emlékek kritikai kiadása" 2004

16 Malov, Sergej Je., "Pamjatniki drevnetjurkskoj pis’mennosti" 1951

17 Ergin, Muharrem, "Orhun Âbideleri [오르콘 기념비들]" 1970

18 Alyılmaz, Cengiz, "Orhun Yazıtlarının Bugünkü Durumu [오르콘 비문들의오늘의 상황]"

19 Ölmez, Mehmet, "Orhon-Uygur Hanlığı Dönemi Moğolistan’daki Eski Türk Yazıtları, Metin-Çeviri-Sözlük [오르콘-위구르 한국(汗國) 시대 몽골에있는 고대 튀르크 비문들, 본문-번역-어휘집]" 2012

20 Tekin, Talat, "Orhon Yazıtları: Kül Tigin, Bilge Kağan, Tunyukuk [오르콘비문들: 퀼 티긴, 빌게 카간, 툰유쿠크]" 1 : 1995

21 Tekin, Talat, "Orhon Yazıtları [오르콘 비문들]" 540 : 1988

22 Aydın, Erhan, "Orhon Yazıtları (Köl Tegin, Bilge Kağan, Tonyukuk, Ongi, Küli Çor) [오르콘 비문들 (쾰 테긴, 빌게 카간, 톤유쿠크, 옹기, 퀼리 초르)]" 87 : 2012

23 Tekin, Talat, "Orhon Türkçesi Grameri[오르콘 튀르크어(= 돌궐어) 문법]" 9 : 2000

24 Li, Yong-Sŏng, "On čẄlgl (or čẄlgIl) in the Kül Tegin and Bilgä Kagan Inscriptions" 2016

25 Erdal, Marcel, "Old Turkic Word Formation: A Functional Approach to the Lexicon I" 7 : 1991

26 Vambéry, Hermann, "Noten zu den alttürkischen Inschriften der Mongolei und Sibiriens, Helsingfors. (= Mémoires de la Société Finno-Ougrienne XII)"

27 Thomsen, Vilhelm, "Mémoires de la Société Finno-Ougrienne V" 1896

28 Clark, Larry V., "Mongol Elements in Old Turkic?" 75 : 110-168, 1977

29 Pulleyblank, Edwin G., "Lexicon of Reconstructed Pronunciation in Early Middle Chinese, Late Middle Chinese, and Early Mandarin" 1991

30 User, Hatice Şirin, "Köktürk ve Ötüken Uygur Kağanlığı Yazıtları: Söz Varlığı İncelemesi [돌궐 및 외튀켄 위구르 카간국 비문들: 어휘 연구]" 32 : 2009

31 Vasil’ev, D. D., "Korpus tjurkskix runičeskix pamjatnikov bassejna Jeniseja" 1983

32 Ajdarov, Gubajdulla, "Jazyk orxonskix pamjatnikov drevnetjurkskoj pis’mennosti VIII veka"

33 Nasilov, Vladimir M., "Jazyk orxono-jenisejskix pamjatnikov" 1960

34 Amanžolov, Altaj S., "Istorija i teorija drevnetjurkskogo pis’ma" 2010

35 Ölmez, Mehmet, "Eski Uygur ve Çin Kaynakları Işığında Orhon Yazıtlarında Geçen Yer ve Kişi Adları [고대 위구르 및 중국 문헌들에 비추어 오르콘 비문들에 나오는 땅 및 사람 이름들]" 2 : 629-640, 2011

36 Aydın, Erhan, "Eski Türk Yer Adları: Eski Türk Yazıtlarına Göre [고대 튀르크 땅이름들: 고대 튀르크 비문들에 따라]" 88 : 2012

37 Orkun, Hüseyin Namık, "Eski Türk Yazıtları IV [고대 튀르크 비문들 IV]" 1941

38 Orkun, Hüseyin Namık, "Eski Türk Yazıtları I [고대 튀르크 비문들 I]" 1936

39 Radlov, Vasilij V., "Drevnetjurkskije pamjatniki Košo-Cajdam, Sbornik Trudov Orxonskoj ekspedicii, T. IV" 1897

40 Nadeljajev, V. M., "Drevnetjurkskij slovar’" 1969

41 Radloff, Wilhelm, "Die alttürkischen Inschriften der Mongolei, Zweite Lieferung" 1894

42 Radloff, Wilhelm, "Die alttürkischen Inschriften der Mongolei, Neue Folge" 1897

43 Radloff, Wilhelm, "Die alttürkischen Inschriften der Mongolei, Erste Lieferung" 1894

44 Radloff, Wilhelm, "Die alttürkischen Inschriften der Mongolei, Dritte Lieferung" 1895

45 Tsogtbaatar, B., "Archaeological Study at the Memorial Site of “Dongoin Shiree” (Results of the archaeological excavations of the project «Ancient Turkic Historical and Archaeological research in the Eastern Mongolia» in 2015 and 2016)" 2017

46 Clauson, Sir Gerard, "An Etymological Dictionary of Pre-Thirteenth-Century Turkish" 1972

47 Thomsen, Vilhelm, "Alttürkische Inschriften aus der Mongolei, in Übersetzung und mit Einleitung" 78 : 121-175, 1924

48 Gabain, Annemarie von, "Alttürkische Grammatik" 1974

49 Tekin, Talat, "A New Classification of the Turkic Languages" 1 : 5-18, 1991

50 Tekin, Talat, "A Grammar of Orkhon Turkic" Indiana University Publications 1968