Penna River in the context of "Nandi Hills, India"

South India, also known as Southern India or Peninsular India, is the southern part of the Deccan Peninsula in India encompassing the states of Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and Telangana as well as the union territories of Lakshadweep and Puducherry, occupying 19.31% of India's area (635,780 km or 245,480 sq mi) and 20% of India's population. It is bound by the Bay of Bengal in the east, the Arabian Sea in the west and the Indian Ocean in the south. The geography of the region is diverse, with two mountain ranges, the Western and Eastern Ghats, bordering the plateau heartland. The Godavari, Krishna, Kaveri, Penna, Tungabhadra and Vaigai rivers are important non-perennial sources of water. Chennai, Bengaluru, Hyderabad, Coimbatore and Kochi are the largest urban areas in the region.

The majority of the people in South India speak at least one of the four major Dravidian languages: Telugu, Tamil, Kannada and Malayalam. During its history, a number of dynastic kingdoms ruled over parts of South India, and shaped the culture in those regions. Major dynasties that were established in South India include the Cheras, Cholas, Pandyas, Pallavas, Satavahanas, Chalukyas, Hoysalas, Rashtrakutas and Vijayanagara. European countries entered India through Kerala and the region was colonized by Britain, Portugal and France.

The Eastern Ghats is a mountain range that stretches 1,750 km (1,090 mi) along the eastern coast of the Indian peninsula. Covering an area of 75,000 km (29,000 sq mi), it traverses the states of Odisha, Telangana, Andhra Pradesh, Karnataka, and Tamil Nadu. The range forms a discontinuous chain of mountains along the eastern edge of the Deccan Plateau, stretching from north of the Mahanadi River in Odisha to Vaigai River in Tamil Nadu at the southern end of the peninsula. The Eastern Ghats meet the Western Ghats at the Nilgiris. The average elevation is around 600 m (2,000 ft) and Arma Konda is the highest peak in the mountains at 1,680 m (5,510 ft).

Geological evidence indicates that the mountains were formed during the archeozoic era and became part of the Indian subcontinent post the break-up of the supercontinent of Rodinia and the formation of Gondwana. The mountains were formed through further metamorphism during the mid-Proterozoic era. The northern section of the range has an elevation ranging from 900–1,400 m (3,000–4,600 ft) and lies mostly in Odisha. The middle section stretches up to the Penna River and consists of two parallel ranges with an average elevation of 520 m (1,710 ft). At the southern end, the range is made up of several smaller hills.

The Kalabhra dynasty (also called Kaḷabrar, Kaḷappirar, Kallupura or Kalvar) were rulers of all or parts of Tamil region sometime between the 3rd century and 6th century CE, after the ancient dynasties of the early Cholas, the early Pandyas and Chera. Information about the origin and reign of the Kalabhras is uncertain and scarce. It is believed that they were once the feudatories of the and the Pallavas. Prof. M. S. Ramaswami Aiyangar, in his 1922 book "Studies in South Indian Jainism" asserted that the Kalabhra period was 'The Augustan age of tamil litrature" He also noted that many Pallava and Pandya records describe how the Kalabhras defeated the Cholas, Pandyas, and Cheras and established their rule. The Kalabhra era is sometimes referred to as the "dark period" of Tamil history, and information about it is generally inferred from any mentions in the literature and inscriptions that are dated many centuries after their era ended.

Historian Upinder Singh states that Shivaskandavarman rise in the 4th century, as evidenced by inscriptions, show Kalabhras were not in power at that time near rivers Penner and Vellar (close to Kaveri). The Kalabhras dynasty had ended for certain by the last quarter of 6th century when Pallava Simhavishnu consolidated his rule up to the Kaveri river, south of which the Pandyas led by Kadunkon consolidated their power. Cholas became subordinates of Pallavas and they were already ruling Telugu region of Rayalaseema.

Coastal Andhra, also known as Kosta Andhra (IAST: Kōstā Āndhra), is a geographic region in the Indian state of Andhra Pradesh, comprising the coastal districts of the state between the Eastern Ghats and the Bay of Bengal, from the northern border with Orissa to Rayalaseema in the south. It includes major cities Visakhapatnam, Vijayawada and Guntur City as well as the state capital Amaravati and is recognized for its fertile lands, rich cultural heritage, and economic importance. Coastal Andhra plays a significant role in the state's agricultural output, particularly in rice and tobacco production, supported by abundant water resources from the Godavari, Krishna, and Penna rivers.

While Coastal Andhra generally includes the districts along the Bay of Bengal, the Uttarandhra (Northern Andhra) area is sometimes regarded as distinct due to its unique cultural and historical background. Coastal Andhra shares borders with the Rayalaseema region of Andhra Pradesh and the state of Telangana. Covering an area of 91,915 square kilometres (35,489 sq mi), Coastal Andhra accounts for 58% of Andhra Pradesh's total area and, as per the 2011 Census of India, hosts a population of over 3.4 crore, constituting 69.20% of the state's population. Coastal Andhra was formerly part of the Madras State until 1953 and then became part of Andhra State from 1953 to 1956.