You can thank the Brits for putting India on the path to s#ithole-dom. Prior to the age of colonization, India was one of the wealthiest regions on the planet.
However the reduction of India to just 2% of world trade in 1947 was not just due to the BRitish -- the British took a lot of India's wealth yes and changed themsevles from a poor land to a rich one (what's the reckoning? They stole about a trillion dollars worth in 2015 currency?)
The izlamik invasions also crushed India and prior to this, the rise of Buddhism led to stagnation.