The phrase "as happened when" is correct and usable in written English.
It can be used to refer to a specific event or situation that occurred in the past, often to draw a comparison or highlight a similar occurrence.
Example: "The project faced several challenges, as happened when we launched our previous product."
Alternatives: "as occurred when" or "as took place when".
But, as happened when the horseless carriage replaced the horses, eventually one will overcome the other.
As happened when Dewey & LeBoeuf filed for bankruptcy last year, the money in those plans could be lost or reduced.
Traders may try to break the peg, as happened when Britain was forced out of the ERM in 1992.
Never again would they humiliate his ministers, as happened when they greeted his health minister during the Gaza war with tomatoes and shoes.
As happened when websites first developed, the far right is again proving to be more innovative than established political groups at harnessing the power of the digital age.
(Still, she and others often stumble on their English, as happened when Aharish couldn't pronounce the word "necessary" from the teleprompter on the air.
He said he was upset that the trustee did not immediately move the commodities accounts to another firm, as happened when other clearinghouses he used went bankrupt.
Some hope that the European Union might be able to curb Mr Erdogan's occasional blunders, as happened when he tried to criminalise adultery last year.
Never again should it be allowed to bring the whole idea of European integration into disrepute, as happened when the Santer commission fell.
And differences in corporate culture can provoke destructive clashes, as happened when the laid-back Swedes of Pharmacia linked arms with the uptight Americans at Upjohn in 1995.
Will the end of despotism give way to chaos - as happened when Mobutu Sese Seko was toppled in 1997 after more than 30 years in power in Zaire?
