Memento Mori’, (remember that you have to die), is the medieval Latin theory and practice of reflection on mortality, especially as a means of considering the vanity of earthly life and the transient nature of all earthly goods and pursuits. Beginning during the aftermath of the Black Death (1346-1353), the allegory reminds those of the vanity of earthly life and the transient nature of all earthly goods and pursuits. The allegory gained popularity during the hundreds of years that the Plague ravaged Europe, returning every generation until the 18th century. The plague left a mark upon the design of tombs and art, resulting in depictions of hourglasses, skulls with wings and skeletons all depicting the one constant that is certain in life, that of death.