The conquest of Sindh occurred as a result of the growing Anglo-Russian rivalry in Europe and Asia and the consequent British fears that Russia might attack India through Afghanistan or Persia.
To counter Russia, the British Government decided to increase its influence in Afghanistan and Persia.
It further felt that this policy could be successfully pursued only if Sindh was brought under British control. The commercial possibilities of the river Sindh were an additional attraction. The road and rivers of Sindh were opened to British trade by a treaty in 1832. The chiefs of Sindh, known as Amirs, were made to sign a subsidiary treaty in 1839.
And finally, in spite of previous assurances that its territorial integrity would be respected. Sindh was annexed in 1843 after a brief campaign by Sir Charles Napier who had earlier written in his diary: ‘we have no right to seize Sind, yet we shall do so, and a very advantageous, useful humane piece of rascality it will be’. He received seven lakhs of rupees as prize money for accomplishing the task.