Short answers, pulled from the story.
The Indian Rebellion of 1857 began on the 10th of May 1857 when Indian soldiers known as sepoys refused to use new Pattern 1853 Enfield rifle-musket cartridges rumored to be greased with cow tallow and pig lard. This dispute over religiously forbidden substances led to the court-martial of 85 men of the 3rd Bengal Light Cavalry and triggered the uprising at the garrison town of Meerut.
Bahadur Shah Zafar was the 81-year-old Mughal ruler residing in Delhi who was pressured by mutinous sepoys to declare himself the Emperor of Hindustan on the 16th of May 1857. His proclamation of war transformed the military mutiny into a broader political struggle but also alienated Sikh communities in the Punjab who feared a return to Islamic rule.
During June 1857, British civilians trapped in Cawnpore were betrayed by Nana Sahib after agreeing to safe passage, leading to the firing of boats on the Ganges River and the murder of survivors in the Bibighar building. The bodies of the murdered women and children were thrown into a well, creating a rallying cry for British reprisals that defined the rest of the conflict.
Rani Lakshmi Bai led rebel forces in Jhansi after the British annexed her kingdom under the Doctrine of Lapse and died on the 17th of June 1858 during the Battle of Gwalior. Her death marked the end of organized resistance in central India while her legacy as a symbol of resistance inspired future generations of Indians to fight colonial oppression.
The Punjab region remained largely loyal to the British because Sikh communities feared a return to Islamic rule under the Mughal Empire and had fought against it during the Second Anglo-Sikh War in 1849. The Punjab Movable Column consisting of British, Sikh, and Pashtun soldiers was instrumental in suppressing the rebellion and provided a secure base of operations for counterattacks.
The Indian Rebellion of 1857 was finally suppressed by the 20th of June 1858 with the defeat of rebels in Gwalior and the British granted amnesty to non-murdering rebels on the 1st of November 1858. The East India Company was dissolved and the Government of India Act 1858 transferred administration of India directly to the British government creating the British Raj.