On 11 May, a small body of cavalry, followed by a larger body in the distance, was seen approaching Delhi along the road between that city and Meerut. The East India Company employees immediately noted that this was unusual, and the senior military officers present within the city attempted to contact Meerut by telegraph to enquire about the approaching troops, but the telegraph line between Delhi and Meerut appeared to have been cut. The 54th Regiment of Bengal Native Infantry, one of three Bengal Native Infantry regiments garrisoned within Delhi's Red Fort, was ordered to intercept them. A party of East India Company civil servants went to secure the fort's Calcutta Gate, but when they arrived they found that troopers from the 3rd Bengal Light Cavalry had already taken control of it. A struggle ensued which led to the death of a cavalry trooper and a civilian. A small group of troopers from the regiment headed toward the city's jail and released the inmates, meeting with no resistance. The main body of the regiment then arrived, joining up with the party at the Calcutta Gate, and then collectively they entered the fort and attacked the civilians within. 

A small group from the advance party gained access to the private courtyard of Bahadur Shah II and told him that he should take command of them. The regiment spread out throughout the fort and the city, and was eventually joined in mutiny by the forces of Bahadur Shah II and members of the Bengal Native Infantry who were based within the fort; a widespread outbreak of looting, burning of buildings and murder of East India Company employees and civilian shopkeepers took place, and the Indian Mutiny began in earnest. The mutineers of the 3rd Bengal Light Cavalry remained at Delhi until the breaking of the Siege of Delhi in September 1857. They withdrew first to Lucknow, then later to Nepal, where the majority of the men died through combat, disease or starvation. Those that eventually managed to make their way back to their homes found themselves shunned by their communities for their part in the War of Independence. The regiment itself, in common with every other regiment of Bengal Light Cavalry, was disbanded at the end of the War of Independence.