The Second Anglo-Sikh War was fought in 1848-49. The English came out victorious in it. As a result, the Punjab was annexed to the British Empire.

Following were the main causes of this war: 

1. Restlessness of the Sikh Soldiers: The Sikh soldiers had to suffer a defeat in the First Anglo-Sikh War. But they knew it well that their defeat was not because they were in any way weaker than the English soldiers but it was due to the treachery of their commanders. Now they wanted to wipe off that disgrace by fighting another war with the English.

2. British Policy of Speedy Reforms: In order to increase their influence in the Punjab, the English, especially Henry Lawrence, the English Resident at Lahore, tried to bring about some social reforms. Laws were framed one after other to end the practice of Sati, to ban the killing of female children and to effect changes in the Zamindari system. Although these reforms were desirable, yet they were brought about in such a haste that the people took them as an undue interference in their religious and social life.

3. Harsh Treatment with Lai Singh and Rani Jindan: The harsh treatment which the English meted out to Rani Jindan enraged the Sikhs. Their anger further increased when the Queen Mother, Rani Jindan was dubbed as a conspirator. She was first sent to Sheikhupura and then exiled to Benaras. The pension of Rani Jindan was reduced from Rs. 1^ lakhs to 48,000 rupees in the first instance and then to? 12,000 annually. Besides, the English also meted out a harsh treatment to the Prime Minister Lai Singh. Such a treatment with Rani Jindan and Lai Singh was too much for the Sikhs to tolerate. So once again, they were forced to take up arms against the English to safeguard their rights.

4. Appointment of British Officers on High Posts: According to the Treaty of Bhairowal, the real powers of the Lahore Kingdom had come in the hands of the English. So they began to appoint English officers on high posts. The Sikh chiefs took this policy of the English as an insult to them. They wanted to free the Punjab from the English yoke.

5. Reduction in the number of Sikh Soldiers: The number of men in the Sikh army ran into lakhs but according to the Treaty of Lahore, their number was reduced to 20 thousand infantry and 12 thousand horsemen. Thus, thousands of soldiers who were disbanded became opponents of the English. Not only this, those soldiers who were kept in service were to be paid lesser salaries. Thus the entire fchalsa army turned against the British. It was filled with anger and began to prepare for another showdown.

6. Revolt of Diwan Mulraj of Multan: After the death of his father, Mulraj became the Governor of Multan in 1844 A.D. He used to pay a tribute of Rs. 12 lakhs a year to the Lahore Darbar in lieu of this post. But, after the Treaty of Bhairowal in December 1846 A.D., the English took over the administration of Lahore. They increased this tribute to Rs. 18 lakhs and also asked him to surrender l/3rd of his territory. Mulraj could not tolerate all this injustice. So he expressed his desire to resign. The English quickly appointed Sardar Kahan Singh as the Governor of Multan. Diwan Mulraj handed over the charge of Multan to the new Governor. The soldiers of Diwan’Mulraj rose in revolt against the English and Diwan Mulraj recaptured Multan. This event led to the revolt against the English in the whole of the Punjab.

7. Revolt of Bhai Maharaj Singh: Bhai Maharaj Singh was the follower of Sant Bhai Bir Singh of Naurangabad. He rose in revoltragainst the English to protect the Sarkar-e-Khalsa. So Henry Lawrence, the British Resident, ordered to put him behind the bars. But he could not be arrested. At the request of Mulraj, he alongwith his 400 horsemen marched towards Multan. But he left Mulraj and joined hands with Chattar Singh Attariwala and his son Sher Singh.

8. Revolt of Chattar Singh of Hazara: Chattar Singh was the Governor of Hazara under the Lahore Government. The English also forced him to rise in revolt. An English officer, Captain Abott, instigated the Afghans of Hazara to revolt against the Sikh State. This British policy of hatching conspiracies led Chattar Singh to take up arms against them in August, 1848 A.D. and join hands with Mulraj.

9. Revolt of Sher Singh: Sher Singh, the son of Chattar Singh who had been sent by the Lahore Government to suppress the revolt of Multan also joined the forces of his father and Mulraj in September 1848 A.D. Thus the revolt against the English spread all over the Punjab. Sher Singh appealed to all the Sikhs to join the rebels to oust the English from the Punjab.

10. Invasion of Punjab by the English: Lord Dalhousie wanted to wage a war against the Sikhs on one pretext or the other and annex the Punjab to the British Empire. Under this policy, he allowed small upsurges by Mulraj, Chattar Singh and Sher Singh to take the form of a big rebellion so that the English could find an excuse to grab the Punjab. The English forces under the command of Lord Hugh Gough crossed the river Sutlej on November 9, 1848 and reached Lahore on 13 November. These forces were engaged in suppressing the rebellion. Thus the Second Anglo-Sikh War began.