May – following the mutiny at Meerut there are outbreaks in Delhi, Ferozepur, Bombay, Aligarh, Mainpuri, Etawah, Bulundshah, Nasirabad, Bareilly, Moradabad, Shahjahanpur and elsewhere; sepoys are disarmed in Lahore, Agra, Lucknow, Peshawar and Mardan; the Delhi Field Force advances to Karnaul; death of General Anson the British commander-in-chief
June – Mutinies at Sitapur, Hansi, Hissar, Azamgarh, Gorakhpur and Nimach; mutinies at Gwalior, Bharatpur and Jhansi; mutiny at Kanpur, followed by the siege of the Europeans and a massacre; mutiny in Banaras forestalled; mutinies at Jewanpur, Allahabad, Jullundur, Phillaur, Nowgong, Rhoni, Fatehgarh, Aurangabad, Fatehpur and Jubbulpur; Indian units are forcibly disarmed at Nagpur and Barrackpur; mutinies at Faizabad, Sultanpur and Lucknow; order is restored in Lucknow but the district remains disturbed ; British defeat at Chinhat near Lucknow; siege of Lucknow begins. Other events of June: Battle of Badli-ki-Serai ; Delhi Field Force takes up position on the Ridge and begins operations against Delhi; further spreading of the revolt through the Gangetic plain, Rajputana and Central India
July – Mutinies at Indore and Mhow, Auggur, Jhelum, Saugor, Sialkot, Dinapur and Agra; siege of the Lucknow Residency continues through July; operations against Delhi continue through July; death of General Barnard, commanding at Delhi ; General Havelock's force advances from Allahabad to the relief of Kanpur and arrives on the 17th, one day too late to save those massacred there; disarming of Indian units in Rawalpindi; Sialkot mutineers defeated at Trimmu Ghat
August – Mutinies at Kolhapur, Poonamali, Jubbulpur, Bhopawar, and Mian Mir ; rebellion spreads through the Saugor and Narbada districts. Also: disarmament of Indian units at Berhampur ; siege of the Lucknow Residency continues and Havelock's first attempt at relief fails
September – Failure of an outbreak in Karachi ; further outbreaks in the Saugor and Narbada districts; siege of Saugor begins; the City of Delhi is assaulted and captured by the British ; the Lucknow residency is relieved by Havelock and Outram but a new siege of the reinforced garrison begins
October – Mutiny at Bhogalpur ; unrest in Bihar, north Bengal and Assam; mutiny in Bombay city is forestalled ; revolt in Kotah state
November – Sir Colin Campbell relieves Lucknow ; the garrison is evacuated and the city and Residency are temporarily abandoned; defeat of General Windham outside Kanpur
December – Decisive battle of Kanpur ; the armies of Rao Sahib and of Tatya Tope are routed by Sir Colin Campbell; campaign in the Doab; capture of Fatehgarh