A caesura is used in Anglo-Saxon poetry to divide a line into two halves. It was used by Old English writers as part of the strong-stress, or accentual, metrical system and represents a pause in the middle of a line of verse that is used to break the rhythmic monotony. The "double pipes" ("||") are used as a symbol to illustrate the caesura when scanning lines of verse in poetry analysis.
The caesura is also often used in Greek and Latin poetry, although it is much more important in Old English poetry, in which the lines are often divided into two halves. The caesura's use in Greek poetry can be found in the opening line of Homer's "Iliad," where it appears as:, "Sing, o goddess, the rage || of Achilles, the son of Peleus."
In Latin poetry, the caesura can be found in Virgil's "Aneid," in the first line for example: "Of arms and the man I sing. || Who first from the shores of Troy..." The term "caesura" is derived from the Latin language. It comes from the Latin root "cedere," which means "hewing off" or "cutting."
The caesura can also be found in other poetic forms and literary eras. For example, the often quoted line by Alexander Pope:, "To err is human; || to forgive, divine."