The sepoys always nursed a strong sense of resentment at their low scale of salary and poor prospects of promotion neither of which had any real correspondence to their worth, particularly when contrasted wth their British colleagues.
Mutiny of Vellore
It was caused by what the sepoys regarded as an affront to their religion. When the new regulations were introduced in the Madras army, forbidding the men to wear the marks of their caste upon their foreheads,ordering them to shave off their beards and compelling them to exchange their old turbans for new ones with leather cockades, the Indian soldiers broke into mutiny at Vellore which with the backing of the members of the exiled family of Tipu Sultan who lived there.
There was another during the first Burmese war.
About the middle of 1824 the 47th native infantry had arrived at Barrackpor in order to take part in some of the operations of Burmese War. The sepoys applied for some assistance to remove their belongings (which were usually taken) but that was refused.This irregular behavior of the authorities highly irritated the sepoys. On 30 Oct they appeared at the parade without Knapsacks and refused to bring even when ordered on the ground they were unfit for use. A part of the regiment demanded double batta. Glasgow Herald on 3rd Nov. gave the details of the scuffle .Mutiny of Sepoys at Barrackpore in 1824. When the Mutiny of Barrackpore brokeout in 1824, the ring leader, a Brahmin of the 27th Regiment Native infantry, was hanged on the edge of the tank where large tree now stands and which was planted on the spot to commemorate the fact.
About a year later disturbances broke out in Assam.
On morning 14th Oct, 1826, the grenadier company refused to march on the pretext of bad climate.The ring leader was seized and put to confinement. Then all the other sepoys demanded to remain in confinement. The court Martial sentenced all the ring leaders.
On 24 Nov, 1838, there were a series of Mutinees due to non-payment of batta. One man in each 10 were punished and dismissed after two years.
In 1839, symptoms of disaffection developed during First Afghan War.
This was on religios ground.