Mushin al-Din Ahmad was born in 1819 in a village of Madaripur of greater Faridpur district. He was popularly known as Dudu Miyan. He was the only son of Shari`at `Ullah. Dudu Miyan took his primary education from his father and then at the age of twelve he traveled to Mecca for further studies. He never achieved the levels of scholarship attained by his father, but Dudu Miyan very soon proved himself an active leader; able to create an effective organizational structure for the Fara`izis in their struggles and reform movements with opposing party and the landlord-planter set of Bengal.

Dudu Miyan spent about five years at Makka for schooling. At the age of 19 he was called back on account of his father`s illness. It was a very critical moment of serious argument of the Faraizis with the landlords, European indigo planters, conventional Ulama and the Sabiqi or the non-Faraizi Muslim society. These communities began to attack the Faraizis individually as well as in collected groups, in which the government supported them. Though less learned than his father, he was youthful, energetic and astutely diplomatic. For all practical purposes he inaugurated an age of his own in the hapless rural society of Faridpur. To face the opposition party, the Faraizis effectively revived the traditional self-governing organization of panchayet system for minimizing conflict in the countryside, to check and control local disputes by good-will compromises and negotiation. For methodical and victorious operation of the panchayet, he took too many precautious measures.

Following the socio-economic policies of his father, Dudu Miyan acknowledged equality and brotherhood of mankind and founded the doctrine of the proprietorship of land as due to the labor. He believed that the land belongs to the tiller. This attracted the attention of all the downtrodden peasantry and irrespective of religion and caste all peasantry followed his ideals and supported him in the Faraizi movement. With the help of his core-khilafat organisation, he took care of all the quarrels of the people in the rural society and settled their disputes, summoned and tried the culprits in the khilafat courts and enforced the judgments efficiently. He even traditionally imposed a verbal injunction against referring any case of the disagreement to the government courts without the permission of the Faraizi Khalifahs on constraint of ensuring non-availability of witness for or against the case.

Unlike his father, Dudu Miyan was active in the world of politics and economics with a direct confront to the status quo. He proclaimed that God was the controller of all land and that the land tax was thus both unlawful and immoral. This declaration was extremely admired among Muslim peasants, but completely offensive to landlords, indigo planters, and the police force. Severe clashes took place in 1841 and 1842, and as a result Dudu Miyan and forty-eight of his followers were arrested, tried, and put into prison. The case proceeded slowly through various stages of petition and finally in 1847 the conviction was set aside by the High Court in Calcutta.

This dramatic victory in the Fara`izi movement greatly increased their prestige and also brought about a decade of peace between them and the landlords. After the break up of the Sepoy mutiny in 1857, the British government captured and imprisoned Dudu Miyan. He was released in 1859, again arrested and finally freed in 1860. By this time he fell seriously ill and died while staying in Dacca in 1862. The death of Dudu Miyan created a vacuum in the movement, which was not quickly filled. The eldest son Mushin al-Din Ahmad, Ghiyath al-Din, was chosen to replace him in 1864, but unfortunately he died later that same year. The second son, `Abd al-Ghafur, popularly known as Naya Miyan, followed his elder brother. Since he was still too young for effective control, three lieutenants became his guardians and supervised the movement until sometime in the 1870s when Naya Miyan took the active leadership of the community. Dudu Miyan lived from 1819 to 1862 but took the leadership of the Faraizi movement at its best after his father Haji shariatullah.