1999–2002 sale of British gold reserves
The sale of the British gold reserve was a policy pursued by HM Treasury between 1999 and 2002, when gold prices were at their lowest in 20 years, following an extended bear market. 395 tonnes of gold, or about half of the reserve, was sold off in a series of auctions, netting the Treasury $3.5 billion.
Source: Wikipedia — 1999–2002 sale of British gold reserves (CC BY-SA 4.0)