<P> On 29 March 1857 at the Barrackpore parade ground , near Calcutta , 29 - year - old Mangal Pandey of the 34th BNI , angered by the recent actions of the East India Company , declared that he would rebel against his commanders . Informed about Pandey 's behaviour Sergeant - Major James Hewson went to investigate , only to have Pandey shoot at him . Hewson raised the alarm . When his adjutant Lt. Henry Baugh came out to investigate the unrest , Pandey opened fire but hit Baugh 's horse instead . </P>
who was the first to declare the mutiny against the british
29 - year - old Mangal Pandey of the 34th BNI