Mazhanadu
Mazhanadu is a region between Tondai Nadu and Karnataka, formerly known as Mazhavarnadu. This region was owned by the Chera Dynasty. It includes the Districts of Salem, Namakkal, Dharmapuri and Krishnagiri. In the ancient sangam age this region was ruled by Mazhavar King Kolli Mazhavan. Famous Sangam poet Avvaiyar had cordial relations with the Mazhavar chieftains like Athiyamān Nedumān Añci of Thagadoor and Valvil Ori of Kollimalai. Mazhanadu was divided into two major divisions, namely Mel-Mazhanadu and Keezh-Mazhanadu. Keezh-Mazhanadu was once ruled by Kolli Mazhavan and his successors, and was well-known for its water resources. It was mentioned in a Tamil poem.
Demographics and Geography
The table below lists geographic and demographic parameters for districts that constitute Mazhanadu.| S.No. | Districts | Headquarters | Established | Area | Population | Population density |
| 1 | Salem | Salem | 1 November 1956 | 5,205 | 3,482,056 | 669 |
| 2 | Dharmapuri | Dharmapuri | 2 October 1965 | 4,497.77 | 1,506,843 | 335 |
| 3 | Namakkal | Namakkal | 1 January 1997 | 3363 | 1,726,601 | 513 |
| 4 | Krishnagiri | Krishnagiri | 9 February 2004 | 5,143 | 1,879,809 | 366 |