The science that enables us to dig the old mounds in a systematic manner in successive layers and to form an idea of the material life of the people is called Archaeology. Yet again history could be written from a number of sources which also include Archaeological Sources. These could be again divided into three groups, namely:
1. Archaeological remains and Monuments

Ancient monuments and ruins recovered during the excavation period are called Archaeological sources. These sources are then subjected to a testing called Radio Carbon dating, also called test in order to ascertain the antiquity of the object found. The lesser the carbon found, the more the antiquity and vice – versa. The half-life of it is 5568 years. Excavations have been conducted at Taxila, Pataliputra, Rajgir, Nalanda, Sanchi, Barhut, Sarnath and Mathura. They are being done at many other places too. Similarly, implements, weaponry, utensils, and tools help us to understand the living and societal conditions of the area.
With regard to the analysis of vegetation, this is called Pollen Analysis or Palynology which comes under the Archaeo-botany sub-specialization of Archaeology that deals with the interactions of humans with plants of past. Here, microscopes are used to study plant pollens present in archaeological layers: these tell us what kind of vegetation, crops or ground cover was present in the layer. One of the oldest samples to have been found is a profile obtained from lake sediments at Lunkaransar, Rajasthan in order to estimate the precipitation in the area. Between 10,500 and 3500 years B.P., the estimated precipitation was about 500 mm/year.
2. Inscriptions

The study and interpretation of ancient inscriptions is called Epigraphy. The study of ancient writing systems and the deciphering and the dating of historical manuscripts are called Paleography. Inscriptions have been found on cave walls, stones, pillar edicts, copper plates, temple walls, bricks. India’s earliest inscriptions are the ones found at Harappa which is yet to be deciphered. The most famous ones include the inscriptions of Asoka at Sanchi. The Hatigumpha Inscription of Kharavela, the Allahabad Pillar Inscription of Samudragupta, and many other rock and pillar inscriptions contain most valuable historical accounts. The taxila and Kalawan copper-plate inscriptions are thought to be some of the earliest instances when copper plates were used to inscribe. As temple and religious institutions began progressing, they were inscribed on the temple walls. Some of the largest collections could be found in the Mysore Museum. Languages used include Prakrits, Sanskrit (from 2nd century C.E). Scripts used include Brahmi and Kharoshti. Inscriptions were also engraved in regional languages in the ninth and tenth centuries.
3. Coins

The study of coins is called Numismatics. Coins in the ancient period were made of silver, lead, gold. Coin moulds during the Kushana period made of burnt clay have also been found. Coins from Greece and Rome of ancient period have been found in Tamil Nadu. They are now stored in museums of Delhi, Lucknow, Mumbai and Chennai. These coins help us in constructing history by providing us with information on the rulers, period, and the social and economic condition. These also indicate trade and commerce based on the area in which they are found. It helps us determine the trade relations between the countries. Some of the coins contain religious and legendary symbols which throw light on the culture of that time. Coins also contain the figures of kings and gods. The largest numbers of coins were issued during the Gupta period.