The primary causes of the First Anglo-Sikh War were the selfish motives of the Sikh nobles on the one hand, and the long-standing ambition of the English to conquer Punjab on the other. The crossing of the river Satlaj by the Sikh army was no genuine cause of the war as the army had not crossed the territory of the English. Even an Englishman, Robert N. Cust described it as “the first British invasion of the independent kingdom of the Punjab”.
- The policy of imperialism of the English and the growing internal weakness of the Sikhs were primarily responsible for the destruction of the kingdom of Ranjit Singh within ten years after his death.
- The internal quarrels among the Sikhs and the desire of the English to draw advantage for themselves created those conditions which resulted in the First Anglo-Sikh War.
- The conspiracies, murders, and conflicts among the members of the royal family for succession to the throne and in-fighting among the nobles finally led to the predominance of the Khalsa army in the affairs of the state within a few years after the death of Ranjit Singh.
- Finally, a minor Dalip Singh under the regency of his mother, Rani Jhindan was placed on the throne while the de facto power of the state passed in the hands of Jawahar Singh and Lal Singh.
- The Rani and the nobles desired to break the power of the Khalsa army by bringing it into conflict with the English.
- The English, on their part, had prepared themselves for the first Anglo-Sikh war so that there were forty thousand soldiers and ninety-four cannons on the border of Punjab when the war started.
- The English were in correspondence with several important Sikh nobles and deputed Major Broadfoot as the political agent to Punjab to create division among the Sikh nobles and also instigate them for war.
- The Sikh army was fearful of English designs assembled on banks of Satlaj.
- The English, on their part, moved their armies from Ambala and Meerut which provoked the Sikhs to cross Satlaj.
- Lord Hardinge then declared war in 1845.
- The Sikhs won only the battle of Buddwal while the English defeated them at the battles of Mudki, Firozpur, Aliwal, and Sobraon and captured Lahore in February 1846.
- The primary reason for the defeat of the Sikhs was the treachery of their leaders and commanders who were in league with the English against their own army.
- The treaty of Lahore signed in 1846 brought no change in the governance of Punjab but the strength of the Sikh army was reduced, most of its cannons were surrendered to the English, a subsidiary English force was kept in Punjab, and Kashmir was sold to Gulab Singh in order to pay the war-indemnity of rupees one and a half crores to the English.