How did the British establish their monopoly over opium trade ?

(i) By 1773, the British government in Bengal had established a monopoly
over opium trade.
(ii) No one else was legally permitted to trade in opium.
(iii) By the 1820s, the British found that opium production in their territories
was rapidly declining and outside its territories, the production was
increasing.
(iv) It was produced in the princely states where local traders were offering
much higher prices to peasants and exporting opium to China.
(v) To the British, this trade was illegal; it was smuggling and it had to be
stopped. Government monopoly had tr-i be retained.
(vi) It therefore, instructed its agents posted in the princely stares to
confiscate all opium and destroy the crops.