What is an Elegy ?

In classical literature an elegy was any poem composed of elegiac distichs , also known as elegiacs, and the subjects were various; death, war, love and similar themes. The elegy was also used for epitaphs  and commemorative verses, and very often there was a mourning strain in them. However, it is only since the 16th c. that an elegy has come to mean a poem of mourning for an individual, or a lament for some tragic event. In England there were few attempts in the 16th c. to imitate elegiacs because the language is unsuited to prolonged series of dactylic hexameters and pentameters. 16th c. French writers like Doublet and Ronsard had the same problem.
Near the turn of the 16th c., the term elegie still covered a variety of subject matter. For example, Donne wrote Elegie. His Picture, and Elegie. On his Mistris. Later the term came to be applied more and more to a serious meditative poem, the kind that Coleridge was hinting at when he spoke of elegy as the form of poetry ‘natural to a reflective mind’. English literature is especially rich in this kind of poetry, which, at times, is closely akin to the lament and the dirge . For instance, the OE poems The Wanderer, The Seafarer and Deor’s Lament, several medieval yrics, Thomas Nashe’s song ‘Adieu, farewell earth’s bliss’, Johnson’s Vanity of Human Wishes, Goldsmith’s The Deserted Village, Gray’s Elegy Written in a Country Churchyard, Young’s Night Thoughts, Keats’s Ode to Melanoholy and Walt Whitman’s When Lilacs Last in the Dooryard Bloomed- to name only a handful of the scores that exist.