The various literary sources for the study of ancient Indian history The importance of coins and inscriptions as a source for history writing is very much. As compare to the literary sources, there are very little chances of manipulating the archaeological sources like coins and inscriptions. Thus the authenticity of the archaeological sources get enhanced. Inscriptions are the most important of all the archaeological sources. Most of the inscriptions of ancient India are found engraved on stone or metal sheets. Due to the engravings on the stone or metal sheet there are almost no chances of manipulation with it. But the problem of dating remains with the inscriptions. The dating is done mainly on the basis of calligraphy of the Inscriptions. The most ancient inscriptions available to us belong to the period of King Ashoka of Mauryan period. These inscriptions throw right on the theories of Kingship of Ashoka and also on his religious ideas. Ashokan inscriptions are mostly in Brahmi script. Some of the ascriptions are also available in Kharoshti and Aramaic script. The inscriptions found after Ashoka can be divided into two groups. Official inscriptions and individual inscriptions. The official inscriptions are either the eulogies written by the court Poets or land charters. At times, there many exaggerations found in these inscriptions. So, they must be used carefully. The inscriptions engraved on the stones or Pillars give us the idea of extent of the empire of a particular King. Individual inscriptions are generally found in the temples or are engraved on the idols. The information’s given on these Idols gives us the idea about their origin. This also throws light on the architecture and sculpture of the period.

The coins are also an important source for the study of history. There are many signs engraved on the ancient coins. There are no other information mentioned on these coins. We don't know the exact meaning of these signs. These coins were probably issued by the traders, trading guilds etc. These coins do not help the historians much. But when the Greek rulers started ruling over the North-Western parts of India, they started issuing coins on which many informations were mentioned. Many a times apart from other informations, the figures of the rulers was also put on the coins. The findings of coins in bulk from one place indicates that the particular place must have been in under one particular state. The dates mentioned on the coins indicate the time period of rulers. The religious figures on the coins give us the idea the religious conditions. The content of gold us the idea about the economic condition.

The Paleolithic or Palaeolithic; pronunciation ;Age, Era or Period is a pre-historic period of human history distinguished by the development of the most primitive stone tools discovered (Grahame Clark's Modes I and II), and covers roughly 95% of human technological pre-history. It extends from the earliest known use of stone tools, probably by Homo habilis initially, 2.6 million years ago, to the end of the Pleistocene around 10,000 BP.

The Paleolithic era is followed in the Mesolithic. The date of the Paleolithic-Mesolithic boundary may vary by locality as much as several thousand years. During the Paleolithic period, humans grouped together in small societies such as bands, and subsisted by gathering plants and fishing, hunting or scavenging wild animals. The Paleolithic is characterized by the use of knapped stone tools, although at the time humans also used wood and bone tools. Other organic commodities were adapted for use as tools, including leather and vegetable fibers; however, due to their nature, these have not been preserved to any great degree. Surviving artifacts of the Paleolithic era are known as Paleoliths.

About 50,000 years ago, there was a marked increase in the diversity of artifacts. For the first time in Africa, bone artifacts and the first art appear in the archaeological record. The first evidence of human fishing is also noted from artifacts in places such as Blombos cave in South Africa. Firstly among the artifacts of Africa, archaeologists found they could differentiate and classify those of less than 50,000 years into many different categories, such as projectile points, engraving tools, knife blades, and drilling and piercing tools. The new technology generated a population explosion of modern humans which is believed to have led to the extinction of the Neanderthals.

Humankind gradually evolved from early members of the genus Homo such as Homo habilis-who used simple stone tools-into fully behaviorally and anatomically modern humans (Homo sapiens) during the Paleolithic era. During the end of the Paleolithic, specifically the Middle and or Upper Paleolithic, humans began to produce the earliest works of art and engage in religious and spiritual behavior such as burial and ritual. The climate during the Paleolithic consisted of a set of glacial and interglacial periods in which the climate periodically fluctuated between warm and cool temperatures. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived in sparsely wooded areas and dispersed through areas of high primary productivity while avoiding dense forest cover.

By 40,000-50,000 BP, first humans set foot in Australia. By 45,000 BP, humans lived at 61° north latitude in Europe. By 30,000 BP, Japan was reached, and by 27,000 BP humans were present in Siberia above the Arctic Circle. At the end of the Upper Paleolithic, a group of humans crossed the Bering land bridge and quickly expanded throughout the Americas.

The term "Paleolithic" was coined by archaeologist John Lubbock in 1865. It derives from Greek: palaios, "old"; and lithos, "stone", meaning "old age of the stone" or "Old Stone Age."

According to Mark Lynas (through collected data), the Pleistocene's overall climate could be characterized as a continuous El Nino with trade winds in the South Pacific weakening or heading east, warm air rising near Peru, warm water spreading from the west Pacific and the Indian Ocean to the east Pacific, and other El Nino markers.

The Paleolithic is often held to finish at the end of the ice age (the end of the Pleistocene epoch), and Earth's climate became warmer. This may have caused or contributed to the extinction of the Pleistocene megafauna, although it is also possible that the late Pleistocene extinctions were at least in part) caused by other factors such as disease and over hunting by humans. New research suggests that the extinction of the woolly mammoth may have been caused by the combined effect of climatic change and human hunting. Scientists suggest that climate change during the end of the Pleistocene caused the mammoths' habitat to shrink in size, resulting in a drop in population. The small populations were then hunted out by Paleolithic humans. The global warming that occurred during the end of the Pleistocene and the beginning of the Holocene may have made it easier for humans to reach mammoth habitats that were previously frozen and inaccessible. Small populations of wooly mammoths survived on isolated Arctic islands, Saint Paul Island and Wrangel Island, till circa 3700 and 1700 BCE respectively. The Wrangel Island population became extinct around the same time the island was settled by prehistoric humans. There's no evidence of pre-historic human presence on Saint Paul Island (though early human settlements dating as far back as 6500 BCE were found on the nearby Aleutian Islands)