What is an epigraph? And what is the difference between an epigraph, an epitaph, and an epigram? We’re here to define the epigraph and differentiate it from its near-homophonous neighbours in the dictionary. So, before we launch into a full introduction to the epigraph and its usefulness for writers, let’s distinguish between epigraph, epitaph, and epigram.
An epigraph is a short quotation at the start of a book or chapter. Usually this is a quotation from a different author; so, for instance, T. S. Eliot begins his 1922 poem The Waste Land with an epigraph from the Roman satirist Petronius’ work.
An epitaph is an inscription on a tomb.
An epigram is a pithy or witty saying, often in verse.
Now we’ve cleared that up, let’s return to the first of these: the epigraph. For the definition of ‘epigraph’ which we provided doesn’t tell quite the full story.
The word ‘epigraph’ is ultimately from the Greek meaning ‘to write upon’. The ‘-graph’ bit is the same bit we find in words like calligraphy (‘beautiful writing’), biography (‘life writing’), colygraphia (‘hindering writing’). Okay, that last one is made up: it’s our coinage for writer’s block. But then aren’t all words ‘made up’ to start with? Anyway…
‘Epigraph’ has good reason for having its roots in the ancient Greek for ‘write upon’. For the word initially referred to an inscription, for instance, one on a building, a statue, or even a tomb. (This hasn’t exactly helped people trying to tell epigraph and epitaph apart.) However, most people nowadays who use the word ‘epigraph’ don’t use it in this original sense. Instead, they use ‘epigraph’ to refer to what the OED defines as ‘a short quotation or pithy sentence placed at the commencement of a work, a chapter, etc. to indicate the leading idea or sentiment; a motto.’
This meaning is recent – perhaps surprisingly recent. The OED offers the following sonnet by Elizabeth Barrett Browning (pictured below right) from 1850 as its earliest citation:
‘My future will not copy fair my past’ –
I wrote that once; and thinking at my side
My ministering life-angel justified
The word by his appealing look upcast
To the white throne of God, I turned at last,
And there, instead, saw thee, not unallied
To angels in thy soul! Then I, long tried
By natural ills, received the comfort fast,
While budding, at thy sight, my pilgrim’s staff
Gave out green leaves with morning dews impearled.
I seek no copy now of life’s first half:
Leave here the pages with long musing curled,
And write me new my future’s epigraph,
New angel mine, unhoped for in the world!
Here, epigraph doesn’t refer to an inscription on a tomb or building, but a motto referring to the poet’s own future. However, even this 
meaning, although the dictionary lumps it in with the most widespread sense of the word, isn’t the commonest one.
Instead, the commonest sense or meaning of ‘epigraph’ is that one we began with: a short quotation at the start of a book or chapter.
Usually, an epigraph is designed to prepare us for the text that follows. But this isn’t always the case. For instance, let’s return to the example of T. S. Eliot for a moment. In Eliot’s poetry, the positioning of a particular epigraph just before the start of the poem raises more questions than it settles. Eliot’s ‘The Love Song of J. Alfred Prufrock’ begins with half a dozen lines from Dante’s medieval poem Inferno, which see a medieval Italian politician telling Dante (who is ‘touring’ hell, shall we say, accompanied by the poet Virgil) that he’s only about to tell what he is about to tell the poet because he knows nobody makes it out of hell alive, so Dante can’t go and tell people in the land of the living.
So what? You may ask. But Eliot’s poem isn’t set in hell, or about medieval Italian politicians, or anything similar to what Dante’s is about. It’s about a middle-aged man hesitating to ask a particular question (possibly asking a girl to marry him), while he attends various tea parties and other social engagements, and frets over his own inadequacy and insignificance. What have Dante’s lines got to do with this?
This is what Eliot wants us to do: to think about the significance of Dante’s lines set in hell to his own poem, set in New England drawing-rooms. Is he implying that the speaker in Dante’s poem (Guido da Montefeltro) and Prufrock are the same in some way? Are they both confiding something to us which they usually wouldn’t dare divulge? Or is it to do with their respective situations? Are they both inhabiting a ‘hell’ of sorts: one literal, the other abstract and metaphorical? Or does Eliot mean to imply a comic contrast: clearly Prufrock lives quite a comfortable life in modern-day New England, and does well enough to pass his time at upper-middle-class tea dances. A bit different from being in the Christian hell for all of time.
It’s impossible to answer these questions, because Eliot’s poem doesn’t explain the relationship between the epigraph and the poem itself.
An epigraph, then, is usually intended to offer us an introduction to the text that follows. But sometimes, especially in modern and contemporary poetry, the relationship between epigraph and poem is more complex and subtle. This shows us the literary power of the epigraph: it can be used to broaden and enrich the literary text itself, by bringing another text (or a short excerpt from another text) into its orbit.
It’s worth concluding by pointing out that the OED’s definition of ‘epigraph’ – for the more recent sense of the word – states that an epigraph can be a quotation at the start of a book or chapter or a pithy sentiment. Since an ‘epigram’ is a witty or pithy saying, one can see how ‘epigraph’ and ‘epigram’ also get conflated by many people. Finally, as if to complete the confusion, it’s worth noting that the initial meaning of ‘epigram’ offered by the OED is ‘an inscription, usually in verse’. At least it doesn’t mention tombs.