The most northerly and second largest constituency in England, covering the towns of Berwick, Alnwick, Wooler and Rothbury, plus a large swathe of rural Northumberland.
Sparsely populated, with an electorate of around 57,000 living in approximately 1,000 square miles.
Sir Alan Beith (Liberal Democrats) won the seat in 2010. He was first elected in 1973 and has built large personal following over the decades. He is now standing down as an MP. The big question: can the Liberal Democrats maintain their hold here or will the high-profile Conservative candidate Anne-Marie Trevelyan take the seat?
The 2010 result:
Liberal Democrats:16,806 (43.7%)
Conservative: 14,116 (36.7%)
Labour: 5,061 (13.2%)
BNP: 1,213 (3.2%)
UKIP: 1,243 (3.2%)
Majority: 2,690 (7%)
The 2015 candidates:
Nigel Coghill-Marshall (UKIP)
Scott Dickinson (Labour)
Julie Pörksen (Liberal Democrats)
Rachael Roberts (Green)
Anne-Marie Trevelyan (Conservative)
Neil Humphry (English Democrats)