"Nearly 200,000 cannabis plants with an estimated street value of between £115-£130 million ($147 million-$166 million, 135 million-152 million euros) were seized," police said.
Around 1,000 people were arrested and of those "more than 450 were later charged," they added.
"Operation Mille" saw searches and arrests carried out across England and Wales "at a scale and pace not seen before," according to authorities.
Cannabis production is a cash cow for organized crime, investigators say, fueling gang violence as groups compete for territory.
"Organized networks involved in cannabis production are also directly linked to an array of other serious criminality such as class A drug importation, modern slavery and wider violence and exploitation," said Steve Jupp, the National Police Chiefs' Council lead for serious organised crime.
"This operation not only successfully disrupted a significant amount of criminal activity, but the intelligence gathered will also help inform future law enforcement activity across the country."
Officers also seized 20 firearms and 26 kilos of cocaine with a potential street value of £1 million.
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