The twin cities of Rawalpindi and Islamabad lie against the backdrop of Margalla Hills on the Potohar plateau. On the basis of archaeological discoveries, archaeologists believe that a distinct culture flourished on this plateau as far back as 300,000 years. Based upon the stone implements found in Soan Valley, researchers have revealed various aspects of activities of the primitive human being. The earliest tools struck from large pebbles have been named as "Pre-Soan". The later tools have been named as "Early-Soan" and "Late-Soan", when better and finer tools were made during Paleolithic period. In the new Stone Age known as Neolithic Culture (10,000 to 5,000 BC), finer and polished stone tools made by early human being have been discovered near Khanpur and some Neolithic burials of long Homo sapiens near Rawat. These discoveries are comparable to "Cromerian" tools of Paleolithic period discovered in Europe.
Serai Khola, located 03 kms southwest of Bhir Mound, is considered as the earliest settlement of Taxila. The discovery of stone celts, chert blades, cores, stone arrow heads, scrapers, terra-cotta animals and female figurines, clay bangles, stone and paste beads, copper pins and wide range of pottery has pushed the history of Taxila from 600 BC to 3000 BC. Three cultural sequences, namely, historic at top, Kot Dijian in the middle and late Neolithic at the bottom have been discovered at Serai Khola near Taxila.
The material remains found on the site of the city of Rawalpindi prove the existence of a Buddhist establishment contemporary to Taxila but less celebrated than its neighbour. It appears that the ancient city went into oblivion as a result of the Hun devastation. The first Muslim invader, Mahmood of Ghazni (979-1030 AD), gifted the ruined city to a Gakkhar Chief, Kai Gohar. The town, however, being on invaders' route, could not prosper and remained deserted until Jhanda Khan, another Gakkhar Chief, restored it and gave the name of Rawalpindi after the village Rawal in 1493 AD. Rawalpindi remained under the rule of Gakkhars till Sikhs defeated Muqarrab Khan, the last Gakkhar ruler, in 1765 AD. Sikhs invited traders from other places to settle here. This brought the city into prominence.
Sikhs lost the city to British in 1849 AD. It then became the General Headquarters of British Army and they established a cantonment south of the old city. In 1879, the Punjab Northern Railway was extended to Rawalpindi but the train service was formally inaugurated on January 01, 1886. Over the years, Rawalpindi has retained its traditional flavour. However, some modern residential areas and buildings have come up all over the town since the creation of Pakistan. Pakistanís new capital, Islamabad, being the twin city of Rawalpindi, equally shares the same archaeological and historical background.