Along with the Bronze Age civilisations of Ancient Egypt and Mesopotamia, the Indus Valley Civilization was one of three early cradles of civilisations of the Old World, and among the three, not only the eldest but also the most widespread, covering an area of roughly 280,000 square miles. Making it’s first appearance shortly before 3000 BC, it flourished from 2600 to 1300, BC ca, and at it’s peak it encompassed much of what is nowadays Pakistan, western India and northeastern Afghanistan, extending from the Pakistani region of Baluchistan in the west to the northern Indian state of Uttar Pradesh in the east, and from northeastern Afghanistan in the north to the west Indian state of Maharashtra in the south. The Indus Valley Civilization urban settlements were linked by the Indus river and prospered in its basins. The Indus River flows south from Karakoram and the Himalayan Mountains through present-day Kashmir and the length of Pakistan, and along a system of perennial, mostly monsoon-fed rivers, to the Indian Ocean. AridIfication of this region during the 3rd millennium BC may have been the initial spur for the urbanization associated with the civilization, but eventually also reduced the water supply enough as to cause the civilization's demise, thus initiating the displacement of its population eastwards. The Indus Valley Civilization, often abbreviated as IVC, is also widely known and named as Harappan Civilization after the archaeological site of Harappa, the first site to be excavated in the 1921, in what was then the Punjab province of British India and is currently Pakistan. The discovery and excavation of Harappa, and soon afterwards, of Mohenjodaro in 1922, a site in the Sindh province of nowadays Pakistan, brought to light the remains of large urban settlements with important breakthroughs occurring as recently as 2010. During this period there have been traced and researched over 1,056 cities and settlements, out of which 96 have been unearthed and partially excavated, mainly in the general region of the Indus and Ghaggar-Hakra Rivers and their tributaries.