The documented history of Indian religions begins with the historical Vedic religion, the religious practices of the early Indo-Iranians, which were collected and later redacted into the "Vedas". The period of the composition, redaction and commentary of these texts is known as the Vedic period, which lasted from roughly 1750 to 500 BCE. The philosophical portions of the Vedas were summarized in Upanishads, which are commonly referred to as "Vedānta", variously interpreted to mean either the "last chapters, parts of the Veda" or "the object, the highest purpose of the Veda". The early Upanishads all predate the Common Era, five of the eleven principal Upanishads were composed in all likelihood before 6th century BCE, and contain the earliest mentions of "Yoga" and Moksha.