Who is Richard castle?

Richard Castle is a fictional character and the protagonist of the television series "Castle," which aired from 2009 to 2016. He is a successful mystery novelist who partners with NYPD detective Kate Beckett to solve homicides, using his creative insights to aid in investigations. The character is known for his charm, wit, and romantic tension with Beckett, which develops throughout the series. Castle's character is portrayed by actor Nathan Fillion.