Piven will reprise his role of the titular businessman, while Kelly will be back as Lady Mae Loxley in the 10-episode season.
Also returning for Season 4 will be series regulars Tom Goodman-Hill, Ron Cook, Amanda Abbington, Amy Beth Hayes, Trystan Gravelle, Sacha Parkinson and Samuel West.
18:15 Will alum Patrick Ewing be Georgetown Hoyas' next head coach?18
14:29 Pirates' Jung Ho Kang denied work visa, questionable for 2017 season13
07:01 Feature phones may be 'dumb' but they're getting 4G LTE25
04:08 Memphis Grizzlies' Chandler Parsons (knee) expected to miss rest of season23