What is the origin of epigraphs?

Question

What are the origins of putting epigraphs in a work?

Wikipedia has this example from 1700, but no explanation on when or why epigraphs came into vogue.

Facsimile of the original title page for William Congreve's The Way of the World published in 1700, on which the epigraph from Horace's Satires can be seen in the bottom quarter.

Answer 1

The first known epigraph was used in Froissart's "Chroniques" about 1404 and «Calendarium» of Regimontan at 1476.

Э. стали применяться в лит-ре с нач. 15 в., впервые, насколько известно, в кн. «Хроники» («Chronique», написана к 1404, опубл. 1495) Ж. Фруассара, «Calendarium» Реджомонтано (Венеция, опубл. около 1476), «Максимы» (1665) Ф. де Ларошфуко («Наши добродетели — это чаще всего искусно переряженные пороки»).
_{- Russian source}

Epigraphs began to be used in literature from the beginning of the 15th century. The first known appearance of an epigraph is in the “Cronique” books (written in 1404 and published in 1495) by J. Froissart, “Calendarium” by Reggomontano (Venice, published circa 1476) and “Maxims” (1665) by F. de La Rochefoucauld (“Our virtues are more often all skillfully dressed vices”).
_{- Russian to English translation}

An image of a page with an epigraph from “Chroniques” is available courtesy of the British Library: