Born on the 12 December, 1984 he began his professional career at Danish side Brondby in 2004. He quickly established himself in the first team as he was one of the key players in the successful 2004-05 campaign. He played two seasons at the club scoring five goals in 49 appearances.
In 2006 he signed for Liverpool after being linked with other European clubs. He signed a four and a half year deal worth £six million. This made him the most expensive player sold by a Danish club. Long term injuries limited his playing time at the club. He played the full 90 minutes in the 2006 Community Shield victory. He competed with Jamie Carragher and Sami Hyypia for the two centre back positions. He netted his first goal for the club in great fashion as he scored from 35 yards out against West Ham United. It was later named the Liverpools Goal of the Season. He has now made over 170 appearances for the Reds.
From 2003 to 2006 he played for the U-20 and U-21 Denmark youth sides. In 2005 he made his international debut and since then he has made over 50 appearances for Denmark. He won the Danish Football Player of the Year in 2007.