Tension between the East India Company and the sepoys (Indian soldiers) of its Bengal Army had been growing for several years, and increased rapidly during 1857.

The first revolt occurred on 10 May at Meerut, 60 miles (97 km) north-west of Delhi, initiated by the 3rd Bengal Light Cavalry,[3] composed mainly of Indian Muslims.

When the first of them arrived on 11 May, they called on the three Bengal infantry regiments there to join them, and for the Mughal Emperor, Bahadur Shah II to lead them.

By the end of the day, Delhi was in rebel hands, and news of the rebellion was spreading rapidly over northern India.

He succeeded in collecting a force at Ambala on 17 May, and they began advancing to Karnal, where most of the British civilians who had escaped from Delhi were taking shelter.

There was severe fighting for the village and serai, but the rebels fled to avoid being surrounded, abandoning thirteen guns.

The sepoys retreated to Delhi in disorder, and some of the citizens thought that the British would follow close on their heels and capture the city before resistance could be organised.

Bahadur Shah had nominated his son Mirza Mughal as commander-in-chief of his army, but the sepoys treated him and the King disrespectfully.

Mirza Mughal was preoccupied with the administration of Delhi, and showed himself to be most unwilling to lead a force to attack Meerut or confront Barnard.

He had not been present at the battle, and later issued a rather fatuous statement that "...as a castle in the game of chess, he was firmly seated beyond all fear of check being given.