Give a brief outline of the major cause of the war of 1857. Where did the war of Revolt begin?

There were many major causes for the Great Uprising of 1857, such as the repressive colonial policies of the British, policies of political expansion like the Doctrine or Lapse and Subsidiary alliances, ill-treatment of the Indian sepoys, decline of Indian markets and heavy taxes. However, the annexation of Awadh and the introduction of Greased Cartridges had pushed the Indians (especially sepoys) over the breaking limit.

The war of revolt started as Mutiny of Sepoys at Meerut on 10th May 1857.