Although the Greeks invented the use of theatrical dramatic monologues, the poetic dramatic monologue was perfected in the 19th century. First uses are documented in Robert Browning's "My Last Duchess" and "Soliloquy of the Spanish Cloister."
In a dramatic monologue, only one character speaks. The character tends to direct his emotions toward a listener who is either inferred or existing. Revealing insight into the character, a dramatic monologue constitutes the entire poem.
Usually taking on an assertive or argumentative tone, a dramatic monologue allows a listener to further delve into a character's emotions. As a reader of the dramatic monologue, you can openly interpret the character's words. Because the word usage is not strict and concrete, the reader becomes part of the creative process.
Poetic and theatrical monologues are often confused with one another. Although they do share much in common, a theatrical monologue is performed on stage to a large audience. On the other hand, a poetic monologue is directed to only one listener at a time.