The Ramayanam is one of the greatest Hindu epics. It is ascribed to the Hindu sage Valmiki and forms an important part of the Hindu literature, considered to be "Ithihasa". The Ramayana is one of the two great epics of Hinduism, the other being the Mahabharata. It depicts the duties of relationships portraying ideal characters like the ideal father, the ideal servant, the ideal brother, the ideal wife and the ideal king. According to Hindu tradition—and according to the Ramayana itself—the Ramayana belongs to the genre of ithihasa. Like the Mahabharata, the definition of Ithihasa has varied over time; with one definition being that Ithihasa is a narrative of past events which includes teachings on the goals of human life. According to Hindu tradition, the Ramayana takes place during a period of time known as Treta Yuga.