Information on the upcoming installment of iTV's hit TV drama, Downton Abbey, continues to circulate on the web, as the latest news has well-known actor Paul Giamatti joining the Season 4 cast.

According to TVLine, Giamatti is being cast as Harold Levinson, "the maverick, playboy brother of Cora (Elizabeth McGovern) and uncle to Mary (Michelle Dockery) and Edith (Laura Carmichael).

The actor recently earned a Golden Globe for his role as John Adams in the HBO miniseries John Adams. He will reportedly be featured in the Season 4 finale along with guest star Shirley MacLaine (Martha).

The Harold character is described by executive producer Gareth Neame as "free-spirited" and stated that Giamatti and MacLaine will "upset the Grantham's apple cart" in the fourth season.

Giamatti will join new cast members Dame Harriet Walters (old friend of Dowager), Nigle Harman (Green), and Tom Cullen (Mary's new love interest).

Downton Abbey is slated to kick off in the U.S. on Jan. 5, 2014, and run until February 23, 2014. Be sure to keep checking back for more of the latest details on the British-American period piece.

For other Downton dirt related to the upcoming season, be sure to check out the video clip below.

Tags: downton abbey television iTV PBS