ENGLISH
REFERENCE

cross the Rubicon

idiom
Meaning

To make an irreversible decision or to take an action with consequences.


Origin

disputed origin

Refers to Julius Caesar's crossing of the Rubicon to wage civil war with Rome, on January 10, 49 BCE, in violation of law. Suetonius' use of the phrase the die is cast in describing this act popularized the use of that phrase, which was first attributed to the Greek dramatist Menander.

Examples
SIMPLE

Once you sign that contract, you cross the Rubicon.

CONTEXTUAL

By resigning from his secure position to start a risky new business, he knew he had crossed the Rubicon.

COMPLEX

The general understood that by ordering his troops across the river, he had crossed the Rubicon and there was no turning back from the coming war.

Anchors to
Related idioms8entries
  1. 01

    come home by weeping cross

    To return in disappointment, or in a spirit of contrition.

  2. 02

    cross my heart

    A declaration that the speaker is telling the truth.

  3. 03

    cross my heart and hope to die

    Added to a promise or a statement to show how serious one was about being honest in what one said

  4. 04

    cross of gold

    A public policy which puts the interests of the rich ahead of those of the poor.

  5. 05

    cross off

    To strike out; to cross out; to draw a line through.

  6. 06

    cross out

    To strike out (something); to draw a line through (something).

  7. 07

    cross paths

    To be, by chance, in the same physical place at the same time, as a result of two completely separate journeys; to encounter or meet each other.

  8. 08

    cross someone's palm

    To pay for goods or a service.

Last updated April 17, 2026