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 (4–25 June) and a massacre; mutiny in Banaras forestalled; mutinies at Jewanpur, Allahabad, Jullundur, Phillaur, Nowgong, Rhoni, Fatehgarh, Aurangabad (Deccan), 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 (Europeans take shelter in the Residency); British defeat at Chinhat (30 June) near Lucknow; siege of Lucknow begins. Other events of June: Battle of Badli-ki-Serai (8 June); 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 (5 July); 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 (16 July)
August – Mutinies at Kolhapur (Bombay Presidency), Poonamali (near Madras), Jubbulpur, Bhopawar (near Indore), and Mian Mir (near Lahore); rebellion spreads through the Saugor and Narbada districts. Also: disarmament of Indian units at Berhampur (1 August); siege of the Lucknow Residency continues and Havelock's first attempt at relief fails
September – Failure of an outbreak in Karachi (14 Sept.); further outbreaks in the Saugor and Narbada districts; siege of Saugor begins; the City of Delhi is assaulted and captured by the British (14-20 Sept.); the Lucknow residency is relieved by Havelock and Outram (25 Sept.) but a new siege of the reinforced garrison begins
October – Mutiny at Bhogalpur (near Dinapur); unrest in Bihar, north Bengal and Assam; mutiny in Bombay city is forestalled (15 Oct.); revolt in Kotah state (15 Oct.)
November – Sir Colin Campbell relieves Lucknow (17 Nov.); the garrison is evacuated and the city and Residency are temporarily abandoned; defeat of General Windham outside Kanpur (28 Nov.)
December – Decisive battle of Kanpur (6 Dec.); the armies of Rao Sahib and of Tatya Tope are routed by Sir Colin Campbell; campaign in the Doab; capture of Fatehgarh