In this year ʿAbd al-Malik ibn Marwan pressed the Dinars and Dirhams and he was the first to change them in an Islamic manner and that benefited people. The reason for this innovation was that he ordered that paper shipments to the Romans be stamped with [the Qurānic verse] “Say Allah ﷻ is One” and that mention the Prophet ﷺ be made with the date.
That displeased the Roman King who wrote back: “You have made certain changes which if you don’t rescind, you will find our Dinars struck with a mention of your Prophet that will displease you.” That was a threat that ʿAbd al-Malik would not accept. He sent for Khalid bin Yazīd ibn Muʿawiyah to consult him. Khālid’s advice was: “Forbid their Dinars and press a new coinage which mentions Allah ﷻ”. And thus the Dinars and Dirhams were pressed.
Then al-Hajjāj struck Dirhams which included the above mentioned Quranic verse, but the people did not favour that. The stature of the Quran, they argued, was being compromised on coinage that was to be used and touched by infidels. He [al-Hajjāj] forbade anyone else to strike coins, but a Jewish merchant named Samīr struck some anyway. He was taken to be executed, but Samīr argued that his Dirhams had more silver content than al-Hajjāj’s. Then he demonstrated that to the people who were not aware of silver content, but simply weighed coins one against another.
The first to order quality control on the striking of silver and the maintenance of it’s purity wasʿ Amr ibn Hubayr in the days of Yazīd ibn ʿAbd al-Malik. Then Khālid ibnn ʿAbd Allah al-Qasrī during the days of Hishām ibn ʿAbd al-Malik became even more strict. Yusuf ibn ʿAmr was not as strict, but when he once tested the content and found it lacking a unit he ordered that the minters be struck 1000 whips each. There were 100 minters and 100,000 whips were administered.
The Hubayrite, Khalidite and the Yusufite Dirhams were the best coins of Bani al-ʿUmayya, and al-Mansūr would not accept other than these. So the first coinage was identified as “the hated coinage”. Some though argue that the coins identified as “hated” were the ones struck by al-Hajjāj.
The Persian Dirhams were of all different sizes and weights and they used to strike some at a weight of 20 Qirat and others at 12 Qirat and still other at 10 Qirats and these were the variations of the official weights. When Islamic coins were struck, they took the three weights together and found that to be 42 Qirats and then took one third of that as the standard and that is 14 Qirats. And that made the weight of each 10 Dirhams 7 Mithqals.
It was also said that Misʿab bin Zubayr struck a few Islamic coins during the reign of his brother ʿAbd Allah bin Zubayr and that these were taken out of circulation during the reign of ʿAbd al-Malik, but the truth is that ʿAbd al-Malik was the first to strike Islamic coins.