Original: Resentment against colonial rule had been mounting for many years and there had been occasional isolated uprisings against British rule at various times since the British had established themselves in the subcontinent.
Simplified: The British, after battling in Rawalpindi in 1845 had captured Jind Kaur, the widow of Ranjit Singh (the former Ruler of Punjab) - this caused the collapse of Sikh rule and, when the British marched into the Murree area, the local tribes at first welcomed them.