The Rigveda is the oldest known Vedic Sanskrit text. Its early layers are one of the oldest extant texts in any Indo-European language. The sounds and texts of Rigveda have been orally transmitted since the 2nd millennium BCE. The Philological and linguistic evidence indicates that the bulk of the Rigveda Samhita was composed in the northwestern region (Punjab) of the Indian subcontinent, most likely between c. 1500 and 1200 BC, although a wider approximation of c. 1700–1100 BC has also been given.