The Badagas are the largest aboriginal Tribes of the Nilgiri district. Nilgiris was originally a tribal land.
The Badagas live in nearly 303 villages, called "Hattis", throughout the district. Badaga people speak the language called "Badugu." Language has no Script.
Some of the villages  are Kukal, Kadanad, Ithalar, Nundala, Meluru, Hulical, Athikaratty, Melkunda, Kilkundha, Ketti, Thanthanadu, Milidenu, Nandatti, Jakkanari, Aravenu, Thinniyoor, Iyooru, Kannerimukku, Beragany, Pethuva, Jakkatha, Thuneri etc.,
They are also called as Gowdas of  Nilgiris.

Badagas belong to paleolithic period. Neolithic cultures like Dolmens, Cromlech, Cairns, Kistavens, Burrows could be found in many Badaga villages, which is considered as sacred by Badagas("H.B.Grigg,1880:242", "W.Francis, 1908:96", "Thurston, 1913:140"). Ashmound an unique feature of neolithic culture, was in practice with Badagas. Terrace Cultivation an another unique feature of Neolithic culture followed by Badagas and still exists (“Bridget & Raymond Allchin,1968:261”)
Badaga Tribe inhabited Nilgiris thousands and thousands of years ago even before Lord Christ was Born. They are inhabiting in Nilgiris over 5000 B.C ("Shobana Swaminathan 1998:66, Reprint 2005", "R.Sugumaran Vol IV, 2009:5").
Precious Stone Trade was carried on between Indus Valley civilization(3300 B.C) and the Nilgiris. At Mohanja Daro and Harappa, "The beautiful green amazon stone could be found near Doddabetta, Nilgiris." Probably Doddabetta derived from Badaga Words ("Dodda - Big"+ "Betta - Mountain", "Doddabetta"), ("Marshall 1913:32","Sakhare M.R., 1978:39", "Dr.J Halan, 2012:16").

Mouriyan Dynasty
During Mouriyan period(321 B.C - 184 AD) Buddhist Monks entered Nilgiris to spread Buddhism among the Badagas in Nilgiris, where came the tree worship among Badagas("H.B.Grigg, 1880:242", " Dr.J Halan, 2012:146", "R.Sugumaran,  2014:12"). Still there is a place called "Mouria Manae" in Nilgiris, belonging to Badagas.

Kadamba Dynasty
During Kadamba(2AD - 6AD) period, the land revenue and other taxes were collected from Badagas of Nilgiris. Food grains were measured by "Kolaga" and "20 Kolaga" a "Kanduga", "Kolaga" in Badaga is "Koga". Still the word Koga is used by Badaga people. Food grains were paid as a tax to Kadambas("B.L.Rice, 1877:468", "Dr.JHalan, 2012:144", "R.Sugumaran, 2014:12").

The Gangas
Later, during Ganga Dynasty(200 AD to around 930AD), a Ganga general came to Nilgiris in 908 AD saw the Badagas living in Nilgiris; says, can find a Fort near Droog. A Badaga Chief has built the Fort (" Gopala krishnan, 1995:1305"). Gangas Ruled Nilgirs (M.Gopala Krishnan, 1995:203) No doubt Nilgiris was an administrative unit of Gangas("Dr.J Halan, 2012:142", "A. RamaKrishnan, 1993:28", " R.Sugumaran, 2014:12").

The Cholas
Raja Raja Cholan I, was crossing eighteen forests for the sake of his emissary to visit Nilgiris and reached the Nilgiris around 985 - 1014 and found Badagas("K.K.Ramachandran, 1986, Vol II:184", "M.Gopala Krishnan, 1995:206", "Dr.J Halan, 2012:140", " R.Sugumaran , 2014:13").

The Kala
In 1116 A.D. a Badaga King called Kalaraja was ruling Nilgiris. Vishnuvardana of Hoysala Kingdom of Karnataka was the first king to invade Nilgiris, sent his army and tried to threaten the Badagas and ordered to obey him.  
The Brave Badaga King, Kalaraja refused his order and fought with him. In his second invation, Hoysala army killed Kalaraj's son, inspite of his son death Kalaraja refused to obey Vishnuvardana. In third invation, King kala was killed by Hoysalas. Three inscriptions refers to Kala's rule from his fort in Kukal Village("B.L.Rice, 1877: Vol:IV, Chp:2"). It testified that King Kala was ruling from 1116 AD and implied that his ancestors had been living here centuries earlier. King Kala was killed in a "Dhandu(war)",("B.L.Rice, 1877: Vol:IV, 19", " Dr.J Halan, 2012:139", "R.Sugumaran, Vol IV 2011:5,6, Vol V, 2014:13"). The Nilgiris came under Hoysala Empire after Kala Raja's death.

Hoysala Dandanayaka
Perumal Dandanayaka, the great minister of Ballala III of Hoysalas was the builder of Dandanayakakottai. His son Madhava Dandanayaka  was ruling Padinalkunadu in the south of Mysore. According to Nicholson, author of Coimbatore Manual(1898), Dandanayakakottai was constructed in1338 by Madappa Dandanayaka who was ruling Nilgiris and Wyanad. He was followed by his son Ketaya Dandanayaka ruled in1321 and by Singaya Dandanayaka in 1338. They are the Subduer of Nilgiris. Descendants of these were the Nava Dandanayakas, nine brothers and chief among them was Perumal Dandanayaka.("Gopala Krishnan, 1995:210").

Vijayanagara Empire
Later in 13th century, the Hoysala Kingdom was defeated by Vijayanagara Empire("H.B.Grigg, 1880:266"),so Nilgiri came under Vijayanagara Empire. The tax was collected at Dandanayaka Kotae, Which was build during Hoysalas, Which is near Gopichettipalayam, Submerged in the river Bavani. The history of Nilgiris during Vijayanagara period was under two different poligars. The Ummathur and Danayakas. The Ummathur chief held the taluks of Ootacamund and Gudalur while Danayakas held the taluks of Kotagiri and Coonoor adjoining the Coimbatore District("Gopala Krishnan, 1995:211").

Ummattur Chiefs
During 15th and 16th  centuries Ummattur chiefs ruled Nilgiris and Terakanambi near Myore as a subordinate of Vijayanagara empire. They rebelled against he suzerain power to become independent but in vain. Nelekota their important fort in Nilgiris. Certain Ummattur chiefs bore the title Nilgiri Sadaran(Ruler of Nilgiris).("Gopala Krishnan, 1995:212").

Sulthan Rule
Later Nilgiris came under  Sulthan rules after the fall of Vijayanagara Empire("H.B.Grigg, 1880:271"). Later the Dandanayakas in Dandanayakakottae was dependent on Nayakas of Madurai. Hyder Ali attacked the King Virapandya Devan at Dandanayakakottae  and captured the Dandanayakakottae. In the inscriptions its mentioned Nilagiri Sadaran Kotae(the fort of conqueror of Nilgiris). Dandanayakakottae villages along with Nilgiri ws called as Oduvanganadu. Hyder Ali was succeeded by Tipu Sultan("Gopala Krishnan, 1995:213").

The British
Later in 1799, British defeated Tipu Sultan and captured Nilgiris(H.B.Grigg, 1880:272). Mountain tracts were unknown to them till 1818, however tax were collected from Dandanayakakotae("Gopala Krishnan, 1995:223").
Until then Nilgiris was a part of Mysore Province. Later British merged Nilgiris with Madras province after defeat of Tipu Sultan. In post Independence, Nilgiris was permanently merged with Tamilnadu .
In 1800 Buchanan made a one-day visit to Nilgiris, partly describes its climate, forest collection, swidden farming and cattle keeping of the Nilgirians and the lifestyle of Badagaru("Buchanan in 1807:161", " Almanack, 1866", "R.Sugumaran, 2014:15", " Dr.J Halan, 2012:1").
In 1812, Williams Key visited Nilgiris from the plains of Coimbatore(" H.B.Griggs, 1880:XLVIII", " R.Sugumaran, 2014:15", "Dr.J Halan, 2012:2") Wish and Kindersley visited Nilgiri in 1819. John Sullivan visited Nilgiris in 1819 with help from Badagas.
Later in 1819, John Sullivan came to Nilgirs from Coimbatore with help of a Badaga elder named Muthiya Gowder. He first reached Kotagiri, then Ootacamund. An inscription about Muthiya Gowder who guided the Sullivan still exist in Milidane village near Kotagiri. After his arrival The Nilgiris was declared as summer capital of Madras Province.
Sullivan constructed the stone house in 1822. In 1868 Nilgiris was separated from Coimbatore and placed under a commissioner and assistant commissioner. Later commissioner became the Collector.  
After Independence the Nilgiri was a part of the composite Madras presidency and after reorganization of states under linguistic basis in 1956, Nilgiri became a part of (Madras State) Tamilnadu.
      Even before Britishers arrived to Nilgiris, a Portuguese Priest called Rev. Jocome Fierier visited Nilgiris in 1602, he reacheda Badaga Village called Melur("James Wilkinson Breekes, 1873:33",Frederick Price 1908:1, H.B.Grigg 1880:273). He did not stay in Nilgiris. He returned back and informed that he found a group of Tribal people called Badagas and Todas.
Nilgiris was called as Badaga Nad or Badaga Country("Frederick Price, 1908:15,16", "W.Francis, 1908:209", R.Sugumaran, 2014:13").
Lord Hethe worship is in practice since around 1200 year ago i.e., 826A.D. Their principle object of adoration is named as "Hette-du"("James Hough, 1826:97", " Dr.J Halan, 2012:141").
Badaga people distinguished their living place into four categories called Porangadu semae, Thothanadu (Thodanadu became Thothanadu) seemae, Merkunadu seame, Kundae seame, where nearly 303 Villages come under these four seame.
The Badagas have no kolas.
Badaga tribal language called "Badugu" was the contact language between Badagas and other tribal people before Britishers and other community people arrived to Nilgiris.
Many names of places in the Nilgiris District are derived from the Badugu language, e.g., Doddabetta, Coonoor, Kotagiri, Gudaluru, Kunda and Othagae(Ooty), Kattabetu, Kodanadu, Aravenu etc.,
Due to lack of script, Badaga people could not record their history.
In 1814 William Keys came from plains of Coimbatore and reached Denad (Kil Kotagiri). He met a group of Wodeas and had conversations with them and collected information(Dr.J Halan, 2012:2). At the time Nilgiris was a part of Mysore and every transaction was with Mysore.
William Keys, by his obscure notice,  he simply grouped them into three - Badagas, Wodeas, and Toreas migrated from Mysore and thus emerged the factual error (Dr.J Halan, 2012:2). Thus, in 1897, when Edgur Thurston wrote a book called "Anthropological Bulletin" and "Cast and Tribes of South India(reprint) in 1909", he followed work done by William Keys("H.B.Griggs, 1880:XLVIII") and, Edgar Thurston also gave a wrong information that Badagas migrated from Mysore.
Badaga men attended the Toda and kota panchayat ("B.L.Rice, 1877:237", "R.Sugumaran 2014:10").
Many research has been done on Badaga community and one of the important researches was done by a French Linguist Called Christian Pilot Raichoor. She has proved that Badagas are the aboriginal Tribes of Nilgiris and they speak an unique language, not a dialect of any language.
Badagas worship several Hindu deities, including Shiva, but their main deities are Hethai and Ayya. They celebrate Hethai Habba in a grand fashion spread over a month during December–January every year, and the festival is celebrated all over the district. They also celebrate Devva Habba yearly once through out the district, considered as an important festival.