A rumor spread among the sepoys that their rifles were greased with beef and pork fat. To use the cartridges, one had to bite off the end. Hindus (cow sacred) and Muslims (don't eat pork) were outraged. 85 out of 90 sepoys refused to use the cartridges, and were sent to jail. The sepoys marched to Delhi, where they met up with more Indian soldiers. They captured the city of Delhi. This rebellion spread throughout northern India. There was much fighting, and it took a year for the East India Company to regain control.