Ancient Roman Memento Mori mosaic from excavations in the convent of San Gregorio, Via Appia, Rome, Italy. Dates to the 1st century.
The Greek motto gnōthi sauton (know thyself, nosce te ipsum) combines with the image to convey the famous warning:
Respice post te; hominem te esse memento; memento mori. (Look behind; remember that you are mortal; remember death.)