The Rigveda is the oldest of the four Vedas, and is believed to have been composed between 1500 and 1200 BCE.

The Vedas are primarily religious texts, containing hymns, prayers, and rituals associated with the Vedic religion.

The Upanishads are a collection of philosophical and spiritual texts, but they are not considered one of the four Vedas.

The Puranas are primarily narrative texts that recount the lives and deeds of kings, heroes, and gods, as well as provide genealogies and historical accounts.

The Bhagavata Purana is considered the most important Purana, as it focuses on the life and teachings of Lord Vishnu, one of the principal deities in Hinduism.

The Ramayana and the Mahabharata are both epic poems that narrate the lives and deeds of kings and heroes, and are considered sacred texts in Hinduism. They also provide historical accounts of ancient India, and are important sources of information for historians.

The Arthashastra, written by Kautilya, is considered the first historical work in India. It is a treatise on statecraft and political science, and provides valuable insights into the political, economic, and social conditions of ancient India.

The Arthashastra covers a wide range of topics, including political science, statecraft, economic policies, taxation, military strategy, and warfare.

Harshacharita, written by Banabhatta, is considered the first biography in India. It narrates the life and achievements of King Harshavardhana of Kannauj.

The Rajatarangini, written by Kalhana, is a historical chronicle that provides a detailed account of the history of Kashmir from ancient times to the 12th century CE.

Indica, written by Megasthenes, is considered the first travelogue in India. It provides a detailed account of the geography, culture, and society of ancient India.

The Periplus of the Erythraean Sea is a guide to navigation and trade in the Indian Ocean, written by an unknown author in the 1st century CE.

Indica, written by Megasthenes, is considered the first foreign account of India. It provides a detailed description of the geography, culture, and society of ancient India.

The Travels of Fa-Hsien, written by the Chinese Buddhist monk Fa-Hsien, provides an account of Buddhism in India, describes the political and economic conditions of India, and provides a detailed itinerary of Fa-Hsien's travels.

Travels of Ibn Battuta, written by the Moroccan traveler Ibn Battuta, is considered the first Muslim account of India. It provides a detailed description of the geography, culture, and society of India in the 14th century.