Answer:
In 1794, Manchu China was the most populous, rich and vast state by far. China had reached its zenith and its maximum expansion under the reign of Emperor Qianlong, and no one could have anticipated at that time that, only forty-five years later, British forces would bend the Manchu emperors in the First Opium War.
However, Britain and Europe suffered a metamorphosis between 1794 and 1839, a process of continuous change whose end result was unrecognizable compared to the starting point. In less than half a century, England had won the hand of the Manchu Empire and would initiate a process that would put Europe and the Western world at the center of all the maps. However, behind the process that led to the birth of modernity and European predominance was a merchandise of doubtful legality: opium. As I said before, it is this process that Great Britain played a central role, as it was the driving force behind the main exchange with China of Opium, Tea and Manofactures.
