The debut album by Rachel Unthank & The Winterset was released in May 2006. At the end of 2005, Cruel Sister was made Mojo Magazine Folk Album of the Year, proving that traditional music can be commercially successful without being watered down. 

Recorded on a shoe-string budget, Cruel Sister captured honest performances, using basic production values to create a listening experience akin to being in the same room as the performers. The album has won them affection from folk purists, the mainstream music world and from leftfield music circles alike, inspiring the likes of Phil Jupitus to broadcast unaccompanied mining songs on daytime BBC 6 Music. 

Cruel Sister draws on source material from Rachel and Becky's native North-East, with an enigmatic interpretation of The Fair Flower Of Northumber-land, eight-minute album centrepiece Cruel Sister, an ethereal Bonny At Morn, Alex Glasgow's Twenty Long Weeks and a delightful slice of Boxing Day tradition, The Greatham Calling On Song, recorded outside with some Redcar Sword Dancers!