Ala-ud-din Husain Shah (Bengali: আলাউদ্দিন হোসেন শাহ; Persian: علاء الدین حسین شاه ;(1494–1519)[1] was an independent late medieval Sultan of Bengal, who founded the Hussain Shahi dynasty.

[7][8] Francis Buchanan-Hamilton's writings make mention of a manuscript found in the former Bengali capital Pandua which labels Husain as a native of a village named Devnagar in Rangpur who seized an opportunity to redeem the throne of Bengal that his grandfather, Sultan Ibrahim, had held seventy years prior.

[10] However, in the 1990s, coins of a Sultan of Bengal by the name of Nasiruddin Ibrahim Shah (r. 1415/16 – 1416/17) were discovered in Beanibazar, Sylhet which has opened discussion regarding this manuscript once again.

While there are many theories about his origin, he was clearly born of a Bengalee mother and was the first ruler of Gaur who gave encouragement to the newly growing Bengali language.

He showed no discrimination between his Hindu and Muslim subjects and fought several wars with neighboring kings in order to consolidate the unclear frontiers of what was eventually to become Bengal".Sengupta also notes that both Krishnadasa Kaviraja’s Chaitanya Charitamrita and the memoirs of Babur allude to Husain's dark complexion.

[4] On the other hand, the Riyaz-us-Salatin mentions Husain's father Sayyid Ashraf Al-Husaini later inhabiting Termez (in Turkestan) for a long period before settling in the Chandpur mouza of Rarh (western Bengal).

[16] Krishnadasa Kaviraja, who was born during Husain's reign, claims that the latter worked for Subuddhi Rai, a revenue officer in the erstwhile Bengal's capital Gaur, and was severely whipped during the excavation of a lake.

[10] 16th-century Portuguese explorer João de Barros mentions the story of a noble Arab merchant from Aden arriving in Chittagong with an army to aid the Sultan of Bengal in conquering Orissa.

Initially, Husain secretly sympathized with the rebels but ultimately he put himself openly as their head and besieged the citadel, where Muzaffar Shah shut himself with a few thousand soldiers.

According to the 16th-century historian Nizamuddin, the Sultan was secretly assassinated by Husain with the help of the paiks (palace-guards), which ended the Abyssinian rule in Bengal.

[21] According to the Madala Panji, Shah Ismail Ghazi commenced his campaign from the Mandaran fort (in the present-day Hooghly district) in 1508-9 and reached Puri, raiding Jajpur and Katak on the way.

[22] When Gouhar Khan, the Bengali governor of Sylhet (in present-day Bangladesh) died, the district was seized by ruler of the neighbouring kingdom of Pratapgarh, Sultan Bazid.

[23] One of Husain Shah's nobles, a Hindu convert named Surwar Khan was sent to confront Bazid and when attempts at negotiations failed, fought against the Sultan and his allies.

But the Sonargaon inscription of Khawas Khan (1513) is interpreted by a number of modern scholars as an evidence of annexure of at least a part of Tripura by Husain Shah's army.

[17] Under the patronage of Paragal Khan, Husain Shah's governor of Chittagong, Kabindra Parameshvar wrote his Pandabbijay, a Bengali adaptation of the Mahabharata.

Similarly, under the patronage of Paragal's son Chhuti Khan, who succeeded his father as governor of Chittagong, Shrikar Nandi wrote another Bengali adaptation of the Mahabharata.

[32] During his reign, an Islamic scholar known as Shaykh Muhammad ibn Yazdan Bakhsh Bengali visited Ekdala where he transcribed Sahih al-Bukhari and gifted it to the Sultan in Sonargaon.