The Webley is a top-break revolver with automatic extraction. That is, breaking the revolver open for reloading also operates the extractor. This removes the spent cartridges from the cylinder. The Webley Mk I service revolver was adopted in 1887. A later version, the Mk IV, rose to prominence during the Boer War of 1899–1902. However, the Mk VI, introduced in 1915 during the First World War, is perhaps the best-known model.
Firing the large .455 Webley cartridge, Webley service revolvers are among the most powerful top-break revolvers ever produced. Although the .455 calibre Webley is no longer in military service, the .38/200 Webley Mk IV variant is still in use as a police sidearm in a number of countries.