Alat (Ala-at, Ala, Alachin, Alagchin, Alchin, Alchi, Alayundu ("piebald horse"); Chinese Boma 駁馬 "piebald horse", Bi-la, Helai 賀賴, Helan 賀蘭, Heloγ, Hela, Arabic Khalaj and Khalaches, Bactrian Xalaso,) are one of the salient Turkic tribes known from Chinese annals, Bactrian inscriptions, and Arab and Persian medieval geographers as a prominent tribe that played a distinguished role in the history of Eurasia. In "Tang huiyao" the Alat tamga is depicted as  The modern Alats live in Russia in the Altai, Kazakhstan, Turkey, eastern section of the Iranian plateau, India, and Afghanistan, they are known as Alats, Alachins, Alayundu, Khalaj, and Khalaches.
Literature on Alats is very rich, Alats were a subject of study by Tangshu, Jiu Tangshu, Tang Huiyao, N.Ya. Bichurin, S.E.Malov, N.A.Aristov, G.E.Grumm-Grjimailo, Yu.Nemeth, G.Hоworth, P. Pelliot, L Hambis, and others.
In ancient Türkic lexicon the meaning of "skewbald" (horse) is expressed with the terms ala, alagchin, still active now in composite expressions. The Chinese transcription for Alachins E-lo-chji is the earliest transmission for the Alat tribe within the Kazakh Junior Juz and parts of Uzbeks. During the Tang time, the Chinese chroniclers used a Chinese version for "skewbald horses", Boma.
Southern Huns in China
Tongdian states that around 349-370 CE a leader of Southern Huns Heloγ Tou (i.e. Alat Tou), with a title Shanyu, brought his tribe of 35 thousand people to the Former Yan Xianbei state and submitted to its dynasty. The Shanyu Helai Toy was bestowed a title of General Pacifying the West, and settled in the Daizong district. It adds that apparently, the tribe Yanto are their descendants. Yanto lived intermixed with tribe Se[disambiguation needed], therefore they are called Se-yanto (Pin. Xueyantuo), that surname of Kagan clan was Ili-tu, that from generation to generation Se-yanto were a strong tribe, and that Se-yanto was a Tele (Pin. Tiele) tribe. Fang Xuanling in Jin Shu stated that Helai (Alats) were one of 19 tribes of the Southern Hun Shanyu.
According to the Chinese annals, the home of the Eastern Hun tribe Alat was in the basin of the Narym River. From the Alat tribe originated one of the Eastern Hun Shanuys called Helog Tou, i.e. Alat Tou, most likely named after his maternal tribe. Under Arabicized name Khalajes, Alats are known to constitute one of the major tribes of the 5th-6th century CE Hephthalites. Tangshu tells about Alats: "They are north from the Türks, 14,000 li from the Chinese capital. They follow grass and water, but mostly live in the mountains. Their standing army is 30,000 men. There is always snow, and foliage does not fall down. They plough fields with horses. All horses are skewbald colors, therefore the state is also given the same name. They live in the north near a sea. Though they have horses, they do not ride them, but use their milk for food. They are frequently at war with Kirgizes". Jiu Tangshu mentions a tribe of skewbald horses among Basmyls, Kirguts, Tuhsi, etc., who in 638 submitted to the Western Türkic Torok-kagan Du-lu ke-han. Tundyan cites as a comment a fragment from an unknown composition that "Tu-jüe (Türks) call the skewbald horses e-la (а-la), and the state is also called "e-la".
From the story of Abulgazi and description of two Mongolian embassies (in 1233 and 1254) to Alachins, they lived along Yenisei, the sources of Angara, and the east coast of lake Baikal, called by the Chinese chroniclers "Northern sea". Based on annalistic traditions, the author of the "Family tree of Türks" Abulgazi described the country of skewbald horses: "A multitude of Tatar tribes coached along the banks of the Angara-muren, which runs east of the Kirgiz country and runs into the sea. On the seacoast at the estuary of this river is a large city surrounded by settlements where live nomadic tribes in large numbers. Their horses are large... All of them are skewbald in hue, there are no others. Near that city called Alakchin was a silver spring, therefore all caldrons, dishes, and vases were from silver. It is that country that the Uzbeks mean when say: "there is a country where all horses are skewbald, and the stoves are from gold". The Khaljī tribe had long been settled in Afghanistan. A Khilji dynasty of Turko-Afghan Khalaj origin ruled large parts of South Asia from 1290 to 1320, they were the second Muslim dynasty to rule the Delhi Sultanate of India, they are noted in history for repeatedly defeating the warring Mongols and thereby saving India from plundering raids and attacks.
After the Russian revolution in 1917, Alats (Kazakh: Alaş), named after a legendary founder of the Kazakh people, headed a movement of the Turkestan peoples for independence, and created a functioning state of the Kazakh people known as Alash Autonomy that operated between December 13, 1917 and August 26, 1920, controlling roughly the territory of the present day Republic of Kazakhstan, with a capital in Alash-qala (modern Semey). The Alash leaders in December 1917 proclaimed establishment of Alash Orda, a Kazakh government, aligned with the Russian White Army and fought against the Bolsheviks.
In 1919, when the White forces were losing, Alash Autonomous government began negotiations with the Bolsheviks. In 1919–20 Bolsheviks defeated the White Russian forces in the region and occupied Kazakhstan. On August 26, 1920, the new Soviet government disbanded the Alash Autonomy, and established the "Kyrgyz Autonomous Soviet Socialist Republic", later the name was changed in 1925 to "Kazak Autonomous Soviet Socialist Republic" and changed again in 1936 to "Kazakh Soviet Socialist Republic". However, the movement for independence continued, and it continued until 1925, when the war for independence was finally extinguished
Alats are one of the main components of the Turkish people known under the name Alayundu which means "spotted horses", they live in central Turkey. As of 2000, approximately 42,000 speakers of the Khalaj language lived in Iran, per ISO 639-3 their language ia called Turkic Khalaj, to distinguish it from the Indo-Iranian "Khalaj" language. In the Causacus, in Armenia and Azerbaijan are a number of settlements with the name ascending to the Alats, they also are in Uzbekistan and Tatarstan, and in the form Kalat in Khorasan. In Afghanistan, Alats are known as one of the largest Pashtun tribes, the Ghilzais, they were pasturing at the Gazni plateau. In India, Alats are called Ghalzae. In Khorasan, Alats are called Kalat, they are Alats and Alaş in Kazakhstan, and Alats and Alachins in Altai in Russia.
Principal linguistic work on Alat langiage (Khalaj in modern Iran) was done by Gerhard Doerfer, who posited a non-Oguz classification based on specific features such as preservation of three vowel lengths, preservation of word-initial *h, and lack of the sound change *d > y. An example of these features is the word hadaq ("foot"), which has preserved the initial *h and medial *d, versus the Oguz form ayaq. Therefore Alat is an independent language that became distinct very early from the Oguz Turkic languages. Because of these distinct features, scholars speculated that the Alat (Khalaj) is a descendant of the Ogur branch of the Turkic family, but there is no firm scholarly consensus on its affinities.
- History of Afghanistan
- History of China
- History of Kazakhstan
- Alash Orda
- History of Kyrgyzstan
- History of Mongolia
- Mountainous Republic of the Northern Caucasus
- Oghur languages
- Khalaj language
- Sims-Williams, 2005, Some Bactrian Seal-Inscriptions//Afghanistan, ancien carrefour entre l’est et l’ouest, ed. O. Bopearachchi and M.-F. Boussac, pp. 335–46
- Zuev Yu.A., "Horse Tamgas from Vassal Princedoms (Translation of Chinese composition "Tanghuiyao" of the 8th to 10th centuries)", Kazakh SSR Academy of Sciences, Alma-Ata, I960, pp. 124, 132 (In Russian)
- Zuev Yu.A., "Horse Tamgas from Vassal Princedoms", p. 124
- Du You, Tongdian ("Collection of the government statutes") // Series "Shi Tup", Ch. 199; in Cen Zhongmian. Tujue ji shi (Collection of materials on a history Tutjue-Türks). Peking, 1958. p. 695, 697
- Fang Xuanling, "Jin Shu", Series "Bo-na", Peking, 1958 Ch. 97. p. 66b, l. 11b
- Kurbanov A.D., "Hephthalites: (essays on history)", St. Petersburg, European House, 2006, ISBN 5-8015-0203-3; PhD thesis 
- Khalji Dynasty. Encyclopædia Britannica. 2010. Encyclopædia Britannica Online. 23 August 2010.
- Barua, Pradeep (2005). The state at war in South Asia. illustrated. U of Nebraska Press. p. 437. ISBN 978-0-8032-1344-9. Retrieved 2010-08-23.
- Yiliuf H.-M. Ancient Türkic glosses (Scythian words) in written works of ancient authors//Proceedings of the 1st scientific and practical conference "Nomadic civilizations of Central and Northern Asian peoples: History, status, problems", Part 1, Kyzyl – Krasnoyarsk, 2008, pp. 149–177
- Doerfer 1971
- Doerfer, Gerhard (1971). Khalaj Materials. Bloomington, Indiana: Indiana University Publications. ISBN 0-87750-150-5. OCLC 240052.
- Doerfer, Gerhard (1998). Grammatik des Chaladsch. Wiesbaden: Harrassowitz. ISBN 3-447-02865-3.
- Doerfer, Gerhard & Tezcan, Semih (1994). Folklore-Texte der Chaladsch. Wiesbaden: Harrassowitz.
- Johanson, Lars & Csató, Éva Ágnes (1998). The Turkic Languages. London: Routledge.