Monastic life, for spiritual studies or the pursuit of moksha (spiritual liberation) traces it roots to the 1st millennium BCE, in the Vedic tradition. The earliest Hindu monasteries ("mathas") are indirectly inferred to be from the centuries around the start of the common era, based on the existence of Sannyasa Upanishads with strongly Advaita Vedanta content. The "matha" tradition in Hinduism was likely well established in the second half of 1st millennium CE, as is evidenced by archeological and epigraphical evidence.