Wikipedia
Kammanadu (or Kamma-nadu, also Kamma-rashtra) is a region in the Indian state of Andhra Pradesh. The region is spread over the mandals of Bapatla, Narasaraopet and Vinukonda mandals in Guntur district and also covers Ongole and Chirala in Prakasam district. The more specific borders of the region lies between Gundlakamma and Perakamma rivers or can also be described as the region lying between Konidena to Kammametu.
The people that emigrated from kammanadu were referred to as belonging to a kammakula (kamma family). Prominent among them were the general Vennaya-bhatta of the Chalukya emperor Vikramaditya V (r. 1008–1015), and generals Sarvadeva and Chamundaraya of Vikramaditya VI (r. 1076–1126). Terms such as kamma-brahmana, kamma-komati, kamma-sreshti and kamma-kapu are also attested in inscriptions as descriptions of people. The famous poet Pampa (902–941), the author of Pampa Bharata in Kannada, was referred to as a kamma-brahmana. The modern Kamma community is believed to be derived from the kamma-kapus, i.e., Kapus of Kammanadu.