375 Throw down the gauntlet

One Idiom One Day: Throw down the gauntlet

When he challenged my conclusions, he threw down the gauntlet. I was ready for an argument. 

to issue a challenge

Antonymous:
take up the gauntlet: to accept a challenge

The phrase dates back to the 1500s. The word “gauntlet” dates back to the 1300s. It is derived from the French word “gantelet,” describing the heavy, metal gloves worn by knights. They were typically worn into battle and throwing down their gauntlet was the way that they challenged an opponent to a duel. Throwing your glove at the feet of your enemy was seen as an insult. The only way to avenge your honor was to fight the offending party.

The figurative meaning of the phrase dates back the 1700s. Even though a physical gauntlet was no longer used, a challenge was still presented.
In later years the challenge that was presented could be an obstacle that was placed in one’s way. By throwing down the gauntlet you are presenting a challenge and by picking it up you are accepting it.

E.g., Someone finally threw down the gauntlet to the boss regarding the oppressive working conditions in the office.

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