The history of Hinduism is often divided into periods of development. The first period is the pre-Vedic period, which includes the Indus Valley Civilization and local pre-historic religions, ending at about 1750 BCE. This period was followed in northern India by the Vedic period, which saw the introduction of the historical Vedic religion with the Indo-Aryan migrations, starting somewhere between 1900 BCE to 1400 BCE. The subsequent period, between 800 BCE and 200 BCE, is "a turning point between the Vedic religion and Hindu religions", and a formative period for Hinduism, Jainism and Buddhism. The Epic and Early Puranic period, from c. 200 BCE to 500 CE, saw the classical "Golden Age" of Hinduism (c. 320-650 CE), which coincides with the Gupta Empire. In this period the six branches of Hindu philosophy evolved, namely Samkhya, Yoga, Nyaya, Vaisheshika, Mīmāṃsā, and Vedanta. Monotheistic sects like Shaivism and Vaishnavism developed during this same period through the Bhakti movement. The period from roughly 650 to 1100 CE forms the late Classical period or early Middle Ages, in which classical Puranic Hinduism is established, and Adi Shankara's influential consolidation of Advaita Vedanta.