Surya Sen was a mild-mannered mathematics teacher in Chittagong, then a port town in eastern Bengal and now in Bangladesh. His students called him 'Masterda', elder-brother teacher. On the night of 18 April 1930 he turned that classroom respect into a full armed uprising. About 65 young men of his secret group, the Indian Republican Army, split into teams and stormed the town's two armouries โ the police reserve store and the Auxiliary Force depot. They cut the telegraph and telephone lines, tore up railway track, isolated Chittagong from the outside world, hoisted a national flag and proclaimed a provisional revolutionary government, with Sen taking a salute as its head. It was, briefly, dazzling. But the plan had one fatal gap: they seized rifles but could not find the ammunition. Unable to hold the town, the rebels melted into the countryside and regrouped on Jalalabad Hill, where on 22 April the British Army caught and shelled them. Twelve revolutionaries died there; the survivors scattered. Over the next three years the movement kept fighting โ including women like Pritilata Waddedar and Kalpana Datta โ until Sen was betrayed, captured, tortured and hanged on 12 January 1934.