"Darkness" is a poem written by Lord Byron in July 1816 on the theme of an apocalyptic end of the world which was published as part of the 1816 The Prisoner of Chillon collection.

The year 1816 is today known as the Year Without a Summer, because Mount Tambora had erupted in the Dutch East Indies the previous year, casting enough sulphur into the atmosphere to reduce global temperatures and cause abnormal weather across much of north-east America and northern Europe. This pall of darkness possibly inspired Byron to write his poem.

"Darkness" is widely regarded as the first major "Last Man" story written originally in English. It established the post-apocalypse paradigm of a solitary surviving narrator who chronicles the extinction of mankind on the earth. The poem influenced later apocalyptic literature and science fiction, establishing the "Last Man" trope or subgenre.

Byron's poem was written during the Romantic period. During this period, several events occurred which resembled (to some) the biblical signs of the apocalypse. Many authors at the time saw themselves as prophets with a duty to warn others about their impending doom. However, at the same time period, many were questioning their faith in a loving God, due to recent fossil discoveries revealing records of the deaths of entire species buried in the earth.

1816, the year in which the poem was written, was called "the year without a summer", as strange weather and an inexplicable darkness caused record-cold temperatures, across Europe, especially in Geneva. Byron claimed to have received his inspiration for the poem, saying he "wrote it... at Geneva, when there was a celebrated dark day, on which the fowls went to roost at noon, and the candles were lighted as at midnight". The darkness was (unknown to those of the time) caused by the volcanic ash spewing from the eruption of Mount Tambora in Indonesia. The search for a cause of the strange changes in the light of day only grew as scientists discovered sunspots on the Sun so large that they could be seen with the naked eye. Newspapers such as the London Chronicle reported on the panic:

The large spots which may now be seen upon the sun's disk have given rise to ridiculous apprehensions and absurd predictions. These spots are said to be the cause of the remarkable and wet weather we have had this Summer; and the increase of these spots is represented to announce a general removal of heat from the globe, the extinction of nature, and the end of the world.

A scientist in Italy predicted that the Sun would go out on 18 July, shortly before Byron's writing of "Darkness". His "prophecy" caused riots, suicides, and religious fervour all over Europe. For example:

A Bath girl woke her aunt and shouted at her that the world was ending, and the woman promptly plunged into a coma. In Liege, a huge cloud in the shape of a mountain hovered over the town, causing alarm among the "old women" who expected the end of the world on the eighteenth. In Ghent, a regiment of cavalry passing through the town during a thunderstorm blew their trumpets, causing "three-fourths of the inhabitants" to rush forth and throw themselves on their knees in the streets, thinking they had heard the seventh trumpet.