In 1202 A.D. Muhammad Bakhtiyar Khilji invaded and conquered Bengal and became the first governor of the Delhi Sultans. In 1338 A.D. the successful revolt of Fakhruddin Mubarak Shah, the governor of Eastern Bengal. During this period twenty five governors were appointed and six of them issued their own coins.
The coins of Bengal include the coins of the governors, which were mostly of silver. Gold coins found were only of Shamsuddin Firoz Shah and those too were scarce. The coins of the first two of the six governors bore the `Kalima` and the date on the obverse and the name and the titles of the ruler on the reverse side of the coin. The coins were the manifestation of the influence of Delhi in fabric and inscription. The subsequent governors substituted the `Kalima` by the name of the last Khalifa of Baghdad, al-Mustasim.
From 1552 A.D. to 1563 A.D, Bengal was ruled from Delhi by Sher Shah Suri and his family and later independently by the successors of his dynasty. After the Suri dynasty, Bengal was ruled by the Afgan Kararani family till 1576 A.D and then Bengal became the province of Akbar`s empire. The coins which were issued during this period carried a typical mark that distinguished them from the coins of other dynasties. These coins were marked by borders, single or double, circles, squares, lozenges, octagons, hexagons and many foiled or scalloped edges. The obverse side of the coin was generally reserved for expression of the king`s religious position as supporter of the Khilafat. The rulers of Bengal used variously `yamin Khalifah allah Nasir Amir al-momin` (the right hand of God`s vice-regent, aider of the prince of the faithful), `Yamin al-Khilafat` (right hand of the Khilafat), and `Ghau al-Islam wa al-musalmin` (succourer of Islam and the Muslims). This last formula was usually written in `tughra` by weaving the letters into a sort of arabesque. Another variation, `Nasir al-Islam wa al-musalmin` was introduced by Azam Shah. Jalaluddin Muhammad Shah, the son of Raja Ganesh revived the `Kalima` on the coins, which was abandoned on the Bengal coins for about two centuries. The obverse sides of some of his later coins were entirely filled with the `Kalima`. From this time onwards, the `Kalima` had secured a position on the obverse side of the coin and the mint name and the date in Arabic numerals were inscribed below it.
During the reigning period of other rulers, the patterns of the coins were changed. Husain Shah spread his title over the obverse and the reverse side of the coin as he found his titles too long to be accommodated on a single face of the coin. The style established by Husain Shah was imitated by his successors. Shamusuddin Muhammad Shah Ghazi of the Suri dynasty followed the coins of his family and restored the `Kalima` and the name of the Khalifas to their proper places in the obverse area and the margin.
Sometimes, the patterns of the coins were altered as per the direction of the rulers. The titles of the Sultans of Bengal, which always occupied the reverse and sometimes extended over the obverse also, are constructed in the same way as those of the Delhi Sultans. They usually begin with `al-sultan al-azam, but sometimes this were omitted or were substituted by `al-muwayad ba-tayeed al-rahman`. The coins of Bengal sometimes contained the inscriptions as on the coins of Fateh Shah and the sons and grandsons of Husain Shah. These were followed by the accession name and the title `abul mujahid` or `abu-muzaffar` or in the case of Muzaffar Shah `abu-al-nasr`. Thereafter the coins followed the proper name of the king with the titles `Shah` and `al-sultan`. After these inscriptions on the coins the name of the father and sometimes the name of the grandfather of the king were also added.
A usual inscription `min khiraj Bang` was found on the coins of two successive rulers, Jalaluddin Mahmud and Nasiruddin Mahmud. This stood as the proof of the fact that the coins were struck from the tributes received by them from Bang. The coins were coined at Lakhnauti. This was said to be the first known instance of coins struck out of tribute. It seemed that during the reign of these rulers the territory of Bang was not under the direct control of the Sultans. In the later period, Alauddin Husain Shah had issued some interesting inscriptions on his coins as epithets. These coins were issued by him from the beginning of his reign and from several of his mints. They were issued in declaration of his conquests of Kamarupa and Kamta in the east and Jajnagar and Orissa in the west.
An illustrious feature of the coinage of the rulers of Bengal was the number of mints. There were twenty names of the mints and several of these mints were merely synonyms and did not represent separate localities. It was a well known phenomenon in the Muslim history of India that a ruler changed the name of a town to uphold his name or that of his father or celebrate some important event or to gratify a passing whim. Apart from the Arabic scripts, the coins also bore Bengali scripts. The coins were issued in the names of Danujamardana Deva and Mahendra Deva and on them were found the dates, Saka 1339 and 1340. In the later period, the ruling period of Raja Ganesh issued his own coins bearing the Saka years. After the enthronement of Jalaluddin, he issued some silver coins. In the later period, it had been found that the silver coins of Jalaluddin Muhammad Shah and Nasiruddin Mahmud Shah and gold coins of Fateh Shah had the linear of a lion on the obverse side of the coin that replace the Persian inscription.
The coins of Bengal display a strong influence of the coins of Delhi Sultans as they maintained the standard of the coins of Delhi Sultans. Later on, the coins were found of a lower weight. A ten `tankah` was also issued by Jalaluddin Muhammad Shah and this coin is known to be the earliest known coin of any multiple denominations in India. These coins were introduced much earlier in the time of Muhammad Shah Khilji, the Delhi Sultan.
The peculiarity of the coins of the Bengal Sultans was that they were frequently disfigured by countermarks and chisel cuts made by the money changers. These coins were in most of the cases of the poorest quality as they lack artistic form and calligraphy. The Bengal Sultans perhaps did not issue coins in copper as no coin was found in this metal.