The Second Anglo-Sikh War was a military conflict fought between the Sikh Empire and the East India Company, which took place from 1848 to 1849. It resulted in the fall of the Sikh Empire, and the annexation of the Punjab and what subsequently became the North-West Frontier Province, by the East India Company.

On 19 April 1848, Patrick Vans Agnew of the civil service and Lieutenant William Anderson of the Bombay European regiment, having been sent to take charge of Multan from Diwan Mulraj Chopra, were murdered there; within a short time, the Sikh troops joined in open rebellion. Governor-General of India Lord Dalhousie agreed with Sir Hugh Gough, the commander-in-chief, that the British East India Company's military forces were neither adequately equipped with transport and supplies, nor otherwise prepared to take the field immediately. He also foresaw the spread of the rebellion, and the necessity that must arise, not merely for the capture of Multan, but also for the entire subjugation of the Punjab. He therefore resolutely delayed to strike, organized a strong army for operations in November, and himself proceeded to the Punjab. Despite the brilliant successes gained by Herbert Edwardes against Mulraj, and Gough's indecisive victories at the Battle of Ramnagar in November and at the Battle of Chillianwala on 13 January 1849, the stubborn resistance at Multan showed that the task required the utmost resources of the government. At length, on 22 January, Multan was taken by General Whish, who was thus set at liberty to join Gough's army. On 21 February, Gough won a complete victory at the Battle of Gujrat. The Sikh army was pursued to Rawalpindi, where it laid down its arms, and their Afghan allies retreated from the Punjab, leaving the region to the British.

After the victory at Gujrat, Lord Dalhousie annexed the Punjab for the East India Company in 1849. For his services the Earl of Dalhousie received the thanks of the British parliament and was advanced in the peerage to marquess, the usual honor for governors general of India.

The Sikh Confederacy Misls of the Punjab were consolidated into an Empire and expanded by Maharaja Ranjit Singh during the early years of the nineteenth century. During the same period, the British East India Company's territories had been expanded until they were adjacent to the Punjab. Ranjit Singh maintained an uneasy alliance with the East India Company, while increasing the military strength of the Sikh Khalsa Army to deter British aggression against his state and to expand Sikh territory to the north and north west, capturing territory from Afghanistan and Kashmir.

When Ranjit Singh died in 1839, the Sikh Empire began to fall into disorder. There was a succession of short-lived rulers at the central Durbar (court), and increasing tension between the Army, which also saw itself as the embodiment of the state and religion, and the Durbar. The East India Company began to build up its military strength on the borders of the Punjab. Eventually, the increasing tension goaded the Sikh Army to invade British territory, under weak and possibly treacherous leaders.

The hard-fought first Anglo-Sikh war ended in defeat for the Sikh Empire which had to cede parts of the Punjab region to the British.

At the end of the war, the Sikh Empire was forced to cede some valuable territory (the Jullundur Doab) to the East India Company, and Gulab Singh, the ruler of Jammu, was allowed to acquire entire Jammu and Kashmir from the Sikh Empire by a large cash payment to the East India Company. Some of the Sikh Army were forced to make an expedition to oust the Governor of Kashmir in favour of Gulab Singh.

The boy Maharaja Duleep Singh of the Sikh Empire was allowed to retain his throne, but a British Resident, Sir Henry Lawrence, controlled the policy of the Durbar. Duleep Singh's mother, Maharani Jind Kaur, continually tried to regain some of her former influence as Regent and was eventually exiled by Lawrence. While some Sikh generals and courtiers welcomed her dismissal, others resented Lawrence's action. Furthermore, the Sikh Sardars were forced to considerably reduce their territorial and judicial control leaving only four Sardars in charge of the judiciary, with Sardar Chattar Singh Attariwalla controlling the area between the Jhelum and the Indus, Sardar Kahan Singh Mann controlling Lahore, Sardar Ram Singh Jallawala controlling the Chaj Doab, and Sardar Lehna Singh Majithia controlling the Majha including lands south east of the Ravi up to the hills and down to Kasur.