In the year 1808 CE (Common Era as against AD), Buchanon Hamilton, for the first time disclosed the details of the ruins of Pundurunagar. Later, scholars like Donnell, Cunningham, Beveridge threw more lights on this ancient city. Sir Cunningham is credited with identifying Mahastahan, the great Muslim city during the glorious Muslim rule of Bangladesh including about two hundred years of unbroken and completely independent Bangladesh, with the ancient city of Pundurunagar.

A sense of the glory of the ancient independent Muslim sultanate of Bangladesh can be found in the words of Ira M. Lapidus in his book: A History of Islamic Societies, Cambridge, where he cited the fact that independent Muslim kingdom existed in Bengal between 1346 CE and 1576 CE and mentioned that "Muslim scholars, scribes, Sufis, poets and intellectuals flocked to India (from other parts of the world). He wrote further: "In Bengal, Sufi writers and Muslim rulers adopted the local languages. The Hindu classic, Mahabharata, and Arabic and Persian classics, including stories from the Arabian Nights, were translated into Bengali at the order of Muslim rulers. Muslim poets also wrote in Bengali about Hindu deities and myths, using Arabic and Persian loan words. This synthesis of languages and literature was the basis for the emergence of a new literary Bengali language."

Several ancient inscriptions belonging to the Maurya, Gupta, Pal and Sen dynasties reveal the existence of the Pundurus in the Pundurunagar. Unfortunately nothing much is known about them these days. Before the arrival of the Aryans, the Pundurus were the natives of this area. The Barendra region of North Bengal (Bogra, Rangpur, Dinajpur, Rajshahi and Maldah) was the original home of the Pundurus.

Inscriptions discovered in 1931 in Mahasthan reveal that there was a massive famine in Pundurunagar, when the government gave a decree ordering food stuff to be distributed amongst the affected subjects which was to be returned during good times indicating that Pundurunagar was an affluent and humanitarian society. After the Gupta dynasty, king Shashanka formed the powerful Gaur kingdom. After the death of Shashanka, the famous Chinese traveler Wan Chuang came to Pundurunagar in the year 639 CE, when besides seeing different Buddhist institutions, he saw a huge Bihar or Shangharam Bhashu Bihar and a memorial built by Asoka over the body of Buddha. According to him Pundurunagar was an affluent city and its perimeter was six miles. The civilization of Pundurunagar ranks side by side with those of Athens, Babylon, Egypt and that of the Assyrians.

Pundurunagar became Mahasthan during the glorious days of the Muslim Sultanate of Bangladesh. A special attraction of Mahasthan is the Mazhar on top of the Garh. Everyday thousands of men and women come from distant places to visit the Mazhar. Many people do “manat” which is going on for ages, there seems to be no exception and no stop. It appears to be like a place of major pilgrimage for both Muslims and Hindus.

Some historians and the local people are of the opinion that this Mazhar is the Mazhar of Shah Balkhi Mahisawar. Apparently, there are two Mazhars related to Balkhi Mahisawar, one being in Mahasthan and the other being in Sultanganj of Godagari Thana.