cross the Rubicon

1. To make an irrevocable decision; it comes from the name of the river Julius Caesar crossed with his army, thereby starting a civil war in Rome. (See Rubicon.)

Idioms and Phrases

Irrevocably commit to a course of action, make a fateful and final decision. For example, Once he submitted his resignation, he had crossed the Rubicon. This phrase alludes to Julius Caesar's crossing the Rubicon River (between Italy and Gaul) in 49 b.c., thereby starting a war against Pompey and the Roman Senate. Recounted in Plutarch's Lives: Julius Caesar (c. a.d. 110), the crossing gave rise to the figurative English usage by the early 1600s.

Example Sentences

“These indictments cross the Rubicon of American politics, as we now indict the leading opponent of the administration and former President, for acting on the oldest tradition in America — contesting elections,” criminal defense lawyer Robert Barnes told The Washington Times.

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The Rev. Samuel Rodriguez, president of the National Hispanic Christian Leadership Conference, an association of 42,118 U.S. congregations, said Hispanic churches “are about to cross the Rubicon into thriving.”

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No “cross the Rubicon” moment where Trump actually says he wants to overturn the Constitution and become a dictator.

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One rioter, Ronald Sandlin, said before the attack that his purpose was to “stand behind Trump when he decides to cross the rubicon. If you are a patriot I believe it’s your duty to be there. I see it as my civic responsibility.”

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The Southern Poverty Law Center, which tracks extremism throughout the United States, cited the speech from the Young republican president Gavin Wax, who told the Upper East side gala, "We want to cross the Rubicon. We want total war. We must be prepared to do battle in every arena. In the media. In the courtroom. At the ballot box. And in the streets."

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