Short answers, pulled from the story.
William Shakespeare wrote the role of Dogberry specifically for actor William Kempe. Kempe was a comic performer in the Lord Chamberlain's Men theatre company during the late 1500s.
The name Dogberry refers to the fruit of the common dogwood tree, considered lowly and inferior to other edible berries. This naming choice suggests Shakespeare intended to poke mild fun at amateur police forces of that era.
Dogberry generates humor through frequent malapropisms, sometimes called dogberryisms or dogberrys. These errors occur when he attempts to use sophisticated terminology with disastrous results due to his actual lack of education.
Samuel Johnson played Dogberry during the 1880s and 1890s for Henry Irving at London's Lyceum Theatre. His portrayals in 1822 and 1893 reflect this claim according to historical records.
Michael Keaton portrayed Dogberry in Kenneth Branagh's 1993 film adaptation of Much Ado About Nothing. Television audiences saw performances by Michael Elphick, Frank Finlay, and Barnard Hughes over decades.