‘Downton Abbey’ Paul Giamatti Season 4: ‘Sideways’ Actor Joins Cast But Not Until Finale, British Show Also Introduces First Black Character

Paul Giamatti will join 'Downtown Abbey' Season 4 Cast, but not until the show's finale. Other new faces will be featured this season, including the British drama's first ever black character.

'Sideways' actor and Brooklyn-native Giamatti will play Harold Levinson, brother of Elizabeth McGovern's character, Cora Crawley. According to The Daily Mail, Giamatti will portray a Playboy and maverick, which will most likely disrupt the high-brow ways of the Crawley family.

However, Giamatti is currently filming "Spider-Man 2" and will not appear in the show until the series' finale, accompanied by Martha Levinson (Shirley MacLaine), who is his and Cora's mother.

Executive producer Gareth Neame said: "We're excited that Paul Giamatti will be joining us on 'Downton' to play Cora's brother Harold, the rather free-spirited uncle to Mary and Edith."

"We can't wait to see him work alongside Shirley MacLaine, who are both sure to upset the Grantham [family's] apple cart in this year's Christmas Day episode."

In an effort to bring more diversity to the cast, the show will also get its first black character, "Death In Paradise" actor Gary Carr, who will play jazz singer Jack Ross, The Daily Mail reports.

The 26-year-old actor's character is described as a "charming and charismatic" musician.

"His addition will bring interesting twists to the drama which we can't wait for viewers to see in Series 4," Neame said.

Downton creator Julian Fellowes wanted to "open the show up ethnically" this season.

Fellowes said in an interview with the Daily Telegraph: "You have to work it in in a way that is historically believable, but I am sure we could do that."

"Downton Abbey" broke records both in the UK and the US. In the States, it became PBS's all-time highest rated drama, with 12.3 million viewers tuning into the season 3 finale, The New York Post reports. The series has also won several Emmys.

"Downton Abbey" will return in the U.K. this fall, but won't appear on American television screen until January 5.