Itihasas: literally Itihasa means “that which has happened”, and sometimes translated as “history.” The Itihasa literature of Hinduism refers specifically to the two great Sanskrit epics: Ramayana and Mahabharata.

Discussion: The Itihasa texts are very popular and their stories are widely recounted by most Hindu practioners. The Ramayana epic of Sage Valmiki is regarded as older than the Mahabharata epic of Sage Vyasa. The Ramayana (Travels of Rama) is the story of the life of Prince Rama of Ayodhya, who is considered an Avatar (incarnation) of Lord Vishnu. The Ramayana details the birth, youth, marriage, exile and return of Lord Rama as well as His vanquish of the demon king, Ravana. The Ramayana has been translated in many different languages and has also been historically very popular throughout South and Southeast Asia.

The Mahabharata, by comparison, is a much larger epic of 100,000 verses. The word Mahabharata is derived from Maha (great) + Bharata (traditional name of India) is considered by some to be a recounting of ancient Indian history. The central portion of the Mahabharata speaks of a grand civil war between rival cousins: the Pandavas and the Kauravas over the issue of the rightful heirs to the kingdom. The entire epic is written as a practical teaching of Dharma and attempts to bring together all collective knowledge up to the point of its composition. Lord Krishna, the next successive incarnation of Lord Vishnu after Rama, makes His appearance also in the Mahabharata epic, as the brother-in-law of the Pandava prince, Arjuna. The Bhagavad-Gita, the famous dialog between Lord Krishna and Arjuna, is found within the Mahabharata.

References:
http://www.geocities.com/profvk/itihasa.html
http://en.allexperts.com/e/i/it/itihasa.htm
http://en.wikipedia.org/wiki/Ramayana
http://www.sacred-texts.com/hin/rama/index.htm
http://web.utk.edu/~jftzgrld/MBh1Home.html
http://www.geocities.com/Tokyo/Bridg...esh/Mb/mb.html
http://www.geocities.com/harindranath_a/maha/maha.html
http://www.sacred-texts.com/hin/maha/index.htm