The Brits didn't set out to build an Empire, they acquired it first to further their trade of spices and other exotica back to Europe, and then to protect their sea trade routes.
Actually the tea plant is native to India (Assam region) and even to Thailand. The problem was the plants were not nearly as robust as those cultivated for centuries in the mountain of China. Just finished reading For All The Tea In China about Robert Fortune who traveled in China disguised as a mandarin, picking up tea plants to send back to India to see if they could grow them in the mountains of India.
I like green tea as well (especially from Emei Mountain where we lived for three years) and I also like Puerh but the tea I have in my hands right now is my favorite, a Yunnan Golden Tips Red (we call it black) tea I picked up in Kunming a couple of years back. Lots of tea blogs have sprung up since I started one back in 2007. A fascinating subject - tea.