The famous Hogenakal water falls is in Dharmapuri district. Rich in Mango farming, the district also boasts one of the best quality marble stone reserves in the world.
The earliest known chieftain who ruled Tagadur (present Dharmapuri) during the Sangam era, is Adhiyaman Naduman Anji, whose patronage sustained the famous poetess Avvaiyar. The next we hear in the 8th century when the northern parts of Salem District were probably under the Pallavas regime. Subsequently, we hear of the Ganga Pallavas having sway over the western parts of the Salem District. The Western Gangas are also mentioned as having ruled Baramahal during the end of the 8th century.
In the beginning of the 9th Century, the Rashtrakutas gained power and influenced the history of the district for the next two centuries. During the period, the Cholas also rose to power in the south and Aditya-I conquered the Kongunadu in 894 A.D. During 949-950 A.D., the Cholas suffered a defeat from the Rastrakutas whose decline started later after the death of their king Krishna-III. Subsequently, the entire area in Salem District came under the rule of the Cholas. The Gangavadi was then annexed to the Chola territory and placed in charge of an Adigaman Tagadur. The 12th century witnessed the decline of the Chola empire when the Hoysalas rose to power and routed the Cholas from Gangavadi. They are said to have captured Kolar, sacked Kotayur and over ran the western parts of Kongunadu. The Baramahal and Talaget areas apparently still remained with the Cholas. But the Adigaman seems to have practically become free and owed only nominal allegiance to the Cholas. Soundrapandia-I assisted the Yadavas in driving out the Hoysala king, Vira Someswara from the Chola territory.
The history of the 13th Century revolve itself between the Hoysalas and the Pandyas. This portion may be added after when they were attacked from the North by the Yadavas, the Hoysalas retreated towards the South in Kongunadu. It is known that Jatavarman Soundrapandian-I assisted the Yadavas in driving out the Hoysalas king, Vira Someswara, from the Chola territory. But it is doubtful whether he made himself master of the Talaghat area as there are records to show that Vira Someswara's son Vira Ramanatha later ruled the whole of Salem District and the Pandiyas were then eclipsed by the Mohammadan emissaries of the Delhi Sultanate.
Dharmapuri has an average elevation of 468 metres (1535 feet).
It is situated in the northwestern corner of Tamil Nadu and is bounded by Tiruvannamalai and Viluppuram districts on the east, Salem district on the South, Krishnagiri district on the north and the river Kaveri on the west. It is located between latitudes N 11 47 and 12 33 and longitudes E 77 02 and 78 40. The total geographical area of Dharmapuri district is 4497.77 km² which is 3.46% of Tamil Nadu.
Dharmapuri was named as Thagadoor when King Adhiyaman administering the Kongu Nadu; the name itself stating that the district was famous for charity. Yes, "Adhiyaman Avaiyaar paatiku nelli kani thanthaar".