Ad perpetuam rei memoriam
“For the perpetual remembrance of the matter.”
Formula of papal documents
What does “Ad perpetuam rei memoriam” mean?
Ad perpetuam rei memoriam translates as “For the perpetual remembrance of the matter.”
A formula marking a document as a lasting record. It signals that something is meant to be remembered forever.
“Ad perpetuam rei memoriam” word by word
| Latin | English | Grammar |
|---|---|---|
| Ad | for, toward | a preposition that takes the accusative and here expresses purpose |
| perpetuam | perpetual, lasting | adjective (perpetuus, perpetua, perpetuum), accusative feminine singular, agreeing with memoriam |
| rei | of the matter, of the thing | genitive singular of res, “thing, matter”; a fifth-declension noun, so the genitive ends in -ei |
| memoriam | remembrance, memory | accusative feminine singular of memoria, “memory”; the object of the preposition ad |
How to pronounce “Ad perpetuam rei memoriam”
The main difference is in rei: the classical ay-ee sound becomes the softer eh-ee in Church Latin. The stress falls on the third syllable of perpetuam and the second of memoriam.
The story behind it
Word for word the phrase says “for the lasting memory of the matter”. It is a set formula, and its logic is simple: the document exists so that a particular event or decision will not be forgotten.
It is best known as the opening of certain papal documents, whose first words told the reader at once that the text was meant as a permanent record. Over time the same wording was borrowed for other official and commemorative texts.
Today it appears mostly in formal or ceremonial settings, such as plaques, dedications and legal or historical writing that wants to sound solemn and lasting.
How to use “Ad perpetuam rei memoriam”
It suits a foundation stone, a memorial plaque, a dedication in a book or a formal certificate. It works best where the occasion really is meant to be remembered for good.
- Latin
- Ad perpetuam rei memoriam
- English
- For the perpetual remembrance of the matter.
- Source
- Formula of papal documents
- Era
- Church Latin
- Theme
- Memory
Common mistakes
- It is a formula, not a sentence with a verb. The sense “this is written so that it will be remembered” is understood rather than stated.
- Rei is not a plural or a form of “king”. It is the genitive of res, “thing, matter”.
- Shortening it to “ad perpetuam memoriam” still works, but it drops the idea of “the matter” that is being recorded.
- It is not a classical Roman saying, so do not credit it to Cicero or another ancient author.
Questions about “Ad perpetuam rei memoriam”
What does “Ad perpetuam rei memoriam” mean?
It means “for the perpetual remembrance of the matter”. It marks a text or object as a lasting record of something worth remembering.
Where does “Ad perpetuam rei memoriam” come from?
It is a formula found in papal documents, which used it to show that they were meant as permanent records. It is Church Latin, not classical.
How do you pronounce “Ad perpetuam rei memoriam”?
Classically, ad per-peh-TOO-am RAY-ee meh-MOH-ree-am. In Church Latin, rei becomes REH-ee and the rest sounds much the same.
Is “Ad perpetuam rei memoriam” good for a plaque or inscription?
Yes, it is a traditional choice for commemorative inscriptions. Its formal tone suits stone, brass and printed dedications.
More to explore
Translation and grammar checked by Latin Quoter · last reviewed November 2026
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