A collection of hymns that forms part of the ancient sacred literature of India known as the Vedas. It was the earliest and most important of the Vedas, the religious writings of the Aryans at the time of their conquest of northwest India. It contains over a thousand poems of great variety of content, written in Sanskrit. It can be dated loosely to the second half of the 2nd millennium BC. It probably assumed its present form c 1000 BC, and was transmitted orally, with great accuracy, for many centuries. It is the oldest literary document of India. The Rigveda is of the greatest importance of philologists studying Hinduism and its immediate predecessor, Vedism. Its interest to archaeologists is in the information on the Aryan invasions of the 2nd millennium BC and the nature of early Indo-European societies in India.