Who is best known for his dramatic monologue?

Robert Browning a major English poet of the Victorian age, noted for his mastery of dramatic monologue and psychological portraiture.
His most noted work was The Ring and the Book (1868–69), the story of a Roman murder trial in 12 books.
His other books:
- My Last Duchess”
- “The Pied Piper of Hamelin”
- “Rabbi Ben Ezra”
- “Bishop Blougram’s Apology”
- “Fra Lippo Lippi” etc.

Source: Britannica.com