Go behind someone’s back

Meaning

Act secretly, especially against someone's trust.

Usage

Used to criticize sneaky or disrespectful behavior.

Origin & History

Origins and dates here are approximate summaries. Many idioms have disputed or unknown origins, and not every date has been checked against a historical dictionary, so treat specific dates and stories as a starting point rather than a citation.

Medieval court imagery of acts performed without the subject’s knowledge.

Used since at least the 17th century in discussions about betrayal.