Kuru was the name of a Vedic Aryan tribal union in northern Iron Age India, encompassing the modern-day states of Delhi, Haryana, Uttarakhand and western part of Uttar Pradesh, which appeared in the Middle Vedic period (c. 1200 – c. 850 BCE) and developed into the first recorded state-level society in South Asia around 1000 BCE, corresponding archaeologically to the Painted Grey Ware culture. It decisively changed the Vedic heritage of the early Vedic period, arranging the Vedic hymns into collections, and developing new rituals which gained their position in Indian civilization as the orthodox srauta rituals, which contributed to the so-called "classical synthesis" or "Hindu synthesis".