Durga, in her various forms, appears as an independent deity in the Epics period of ancient India, that is the centuries around the start of the common era. Both Yudhisthira and Arjuna characters of the "Mahabharata" invoke hymns to "Durga". She appears in "Harivamsa" in the form of Vishnu's eulogy, and in Pradyumna prayer. Various Puranas from the early to late 1st millennium CE dedicate chapters of inconsistent mythologies associated with "Durga". Of these, the "Markandeya Purana" and the "Devi-Bhagavata Purana" are the most significant texts on "Durga". The Devi Upanishad and other Shakta Upanishads, mostly dated to have been composed in or after the 9th century, present the philosophical and mystical speculations related to "Durga" as "Devi" and other epithets, identifying her to be the same as the Brahman and Atman (self, soul).