to the horns of the altar
Preserved but no longer current.
Usque ad aras amicus. Your friend even to the horns of the altar — i.e. through thick and thin. In swearing, the ancient Romans held the horns of the altar, and one who did so in testimony of friendship could not break his oath without calling on himself the vengeance of the angry gods.
Era: ca. 1898 (Victorian)
Sources & notes
Reproduced from Brewer’s Dictionary of Phrase and Fable (1898 edition, public domain; archive.org, retrieved 2026-07-31; OCR text, minor errors possible). Reflects the scholarship and attitudes of its era.
Common questions
What does “to the horns of the altar” mean?
Usque ad aras amicus. Your friend even to the horns of the altar — i.e. through thick and thin. In swearing, the ancient Romans held the horns of the altar, and one who did so in testimony of friendship could not break his oath without calling on himself the vengeance of the angry gods.
Is “to the horns of the altar” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.