As Jack Colback signs for his boyhood club, Newcastle United, he becomes one of just a handful of players to have played for both Newcastle and local rivals Sunderland.
We look back at who else has crossed the great North East football divide.
- *Len Shackleton *played for Newcastle for two years before moving to Sunderland in 1948. He went on to score 101 times in 348 appearances. He died in 2000.
- Stan Anderson is the only player to captain all three North East clubs - Newcastle, Sunderland and Middlesbrough. He joined Sunderland in 1952 and was a regular for 11 years, including two FA Cup finals in 1955 and 56 and relegation in 1958. He was sold to Newcastle in 1963 and then moved to Middlesbrough in 1965.
- *Bob Moncur *was a Newcastle favourite 1962 and 1974, including helping the club to win the Fairs Cup in 1969: he scored three goals in the final. However, after 12 years there he moved to Sunderland in 1974. He told ITV News Tyne Tees the key to being accepted is to play very well.
- *Paul Bracewell *had three spells at Sunderland between 1983 and 1997 but also played for Newcastle United for three years from 1992.
- *Lee Clark *made 265 appearances in two spells for his boyhood club, Newcastle United. He signed for Sunderland in 1997 but left after being photographed wearing a t-shirt criticising the club. He is now Birmingham City manager.
- *Jack Colback *started his career at youth level with Sunderland, despite being a boyhood Newcastle United fan, and rose up through the ranks to make 104 league appearances. He is expected to be given a long-term contract with Newcastle after making a free transfer.