Editor’s note: This article is the first in a three-part series that explores the evolving role of gold in North Korea’s foreign currency strategy. 

Long before North Korea turned to cybercrime and covert shipping to evade international sanctions, it was quietly reaping billions from a far more conventional source: gold.

Newly unearthed British government records from the 1970s to the 1990s reveal the huge scale of North Korean gold bullion sales and suggest Pyongyang may have mined and refined — and potentially sold — up to a billion dollars’ worth of gold a year.

Much of this was sold in