In late October, PBS said it finished the 2013-14 TV season ranked No. 5 among all broadcast and cable networks in household ratings. The 5% growth from the comparable September 2012-September 2013 period was partly driven by the strong showing of Masterpiece’s Downton Abbey. Masterpiece and PBS now say they are adding at least 20 additional hours of British drama in 2015. The Masterpiece showcase will continue to air in its Sunday 9 PM time slot, with some shows added at 8 PM and others at 10 PM throughout the year.

The enlarged Masterpiece footprint kicks off with Grantchester, ITV‘s six-part mystery that stars James Norton as a charismatic clergyman who turns investigative vicar when one of his parishioners dies under suspicious circumstances (see trailer below). The 1950s-set series has received strong notices from critics in the UK where it is currently airing. It will debut on Masterpiece on January 18, at 10 PM, following Downton Abbey. Grantchester is a Lovely Day and Masterpiece co-production for ITV.

On April 5, highly-anticipated miniseries Wolf Hall, based on the books by Hilary Mantel, will debut. Mark Rylance and Damian Lewis star in the six-part series that charts the rise of Thomas Cromwell (Rylance) from lowly blacksmith’s son to the closest advisor of Tudor king Henry VIII (Lewis). The drama is a Company Pictures and Playground co-production for BBC Two and Masterpiece.

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Other Masterpiece programming scheduled for 2015 includes The Manners Of Downton Abbey, a behind-the-scenes look at the world of Edwardian manners with Alastair Bruce; a third series of Jeremy Piven-starrer Mr Selfridge; a new adaptation of the 1970s blockbuster Poldark, starring Aidan Turner; and the drama Indian Summers, set in the waning years of British colonial rule in 1930s India.

Masterpiece, which is produced by WGBH/Boston, has aired on PBS since 1971 and has seen a surge in popularity in recent years. The audience for the 2014 season is up over 100% from 2010. The expanded slate is funded by an exclusive corporate sponsorship with Viking River Cruises along with additional funding provided by PBS and WGBH.