Final answer:
The Victorian Dramatic Monologue emerged from earlier poetic language, theatrical styles, Restoration plays' extravagance, 19th-century melodrama, and the Realism movement, reflecting the complexities of human character against the socio-cultural changes of the era.
Step-by-step explanation:
The Dramatic Monologue of the Victorian era evolved from several earlier styles of writing and performance, including the artful poetic language and theatrical presentations of the 16th and 17th centuries, the extravagance of Restoration plays, and the melodrama popular in the 19th century. It came as a literary and dramatic form in which Victorian writers, in their quest for Realism, sought to depict the complexity of human character and society. A dramatic monologue is a lengthy speech delivered by a single character, which became an effective tool to explore individual psyches in detailed and realistic contexts, against the backdrop of the changes brought about by the Industrial Revolution which saw a rise in the middle class and their desire for cultural representation that reflected their own experiences.
The Victorian era's pursuit for Realism and more personal writing styles also led to dramatic monologues that drew from the expressive breadth seen in prior forms of literature, theater, and performance. The varied history of the theater, from the classical tragedies and comedies, through the sentimentalism and melodramas of the 18th and early 19th centuries, set the stage for this newer form that would become a hallmark of Victorian literature, as exemplified by Robert Browning's "My Last Duchess".