Dineshchandra Sircar notes that the word nadu was commonly used in south Indian names to indicate that a place was a district. The word Kammanadu is derived from Karmarashtram (Sanskrit) or Kammaratham (Pali).
The region straddled from the southern bank of Krishna river up to Kandukur (Prakasam Dt.). Buddhism flourished in this region from 3rd century BC onwards. Dharanikota, near Amaravati on the bank of Krishna river (Guntur Dt.) was the ancient capital of the Ikshvaku dynasty and the Satavahana dynasty which ruled South India for five centuries.
The region is famous for the exquisite sculpture found in the Buddhist stupas of Bhattiprolu, Nagarjunakonda and Amaravati. The ancient Brahmi script found in the inscriptions at Bhattiprolu (Bhattiprolu script) was the progenitor of modern Telugu, Kannada and Tamil scripts.
The mention of Karmarashtram is noticed first in the inscriptions of Ikshvaku king Madhariputra Purushadatta (3rd century A.D) found at Bethavolu (Jaggayyapeta). The next record is the inscription of Pallava king Kumara Vishnu II, son of Buddha Varma found in the village Chenduluru. The third record is that of Eastern Chalukya king Mangi Yuvaraja (627-696 AD) which goes as:
Srisarvalokasraya maharajah kammarashtre chendaluri grame (Sanskrit)
In all contemporary inscriptions (3rd to 11th century AD) the words Kammarashtram, Kammaratham, Kammakaratham, Karmarashtram, Karmakaratham and Karmakarashtram, Kammakarashtram were interchangeably used.
Pavuluri Mallana, the contemporary of the great king Rajaraja Narendra (1022-1063 AD) wrote:
Ila Kammanati lopala vilasillina Pavuluri vibhudan (Telugu)
The subsequent inscriptions of Telugu Chodas and Kakatiyas mentioned ‘Kammanadu’ (e.g., Konidena inscription of Tribhuvana Malla – 1146 AD). During the rule of the Kakatiya emperor Prataparudra II, one Boppana Kamaya was ruling Kammanadu with Katyadona (Konidena) as the capital.
It is not known clearly when the usage of the word Kammanadu ceased. However, the name survives on as the denomination of the Kamma caste that is predominantly found in the region.
- Burgess, J. 1886, Buddhist Stupas of Amaravathi and Jaggayyapeta, Madras Presidency, Archaeological Survey of India, p. 110.