Taiping Kingdom overthrows the Qing Dynasty, gets into a war with the British Empire over the Opium trade, refuses to negotiate a treaty, and consequently is sacked. Cue the need to establish a British colony for the country, constantly threatened by irregular warfare from quasi-Christian zealots. [I'm writing a timeline with this kind of scenario. I'm actually struggling with whether or not the British would be able to defeat a semi-modernized power with strength in numbers, morale, and terrain.]