Khalid Boulahrouz

In his youth Boulahrouz played consecutively for Excelsior Maassluis, DSOV, Ajax, Haarlem and AZ.

RKC Waalwijk

After a difficult period playing for different clubs, he finally found some stability at Waalwijk, where coach Martin Jol gave him the confidence he had been looking for. He began his professional career in the Dutch Eredivisie for RKC on 9 March 2002, against Heerenveen.

Hamburger SV

After playing two seasons for RKC he moved to Hamburg to play in the German Bundesliga at the start of the 2004–05 season. While at Hamburg, he earned his nickname "Khalid der Kannibale" ("Khalid the Cannibal") for his ability to eat up the opposition. This is illustrated by the number of cards he received – 16 yellows and three reds in two seasons at the club. He was also part of a defence that conceded the fewest goals in the 2005–06 Bundesliga season: 30 goals in 34 games.

Chelsea

On 18 August 2006, Chelsea agreed a fee with Hamburg to sign Boulahrouz. The fee was thought to be around £8.5 million (€12 million). After Chelsea's opening game of the 2006–07 season, manager José Mourinho confirmed that the club had signed Boulahrouz but were waiting for his international clearance to be finalised, before speaking of the potential roles Boulahrouz would have in the side. Mourinho stated "in a short squad and in a country where you can have only 16 players for a match, it’s important to have cover for many positions." On 21 August 2006, Chelsea completed…

Boulahrouz' displays for RKC caused Marco van Basten to pick him for the Netherlands national football team. He made his international début on 3 September 2004 in a 3–0 win for the Netherlands against Liechtenstein, and was named in the squad for the 2006 World Cup. He managed 34 caps for the national team, as of November 2011. Boulahrouz was sent off from the Netherlands match against Portugal in the 2006 FIFA World Cup Round of Sixteen after a second bookable offence. He was judged to have used an elbow on Portugal's Luís Figo. Before that, he was first booked in the seventh minute after a violent tackle that injured Cristiano Ronaldo, eventually forcing the substitution of the Portuguese player. Referee Valentin Ivanov issued a total of 16 yellow cards and four red cards in this match, a World Cup record. Having initially missed the cut for the Dutch Euro 2008 squad, following an injury to Liverpool's Ryan Babel, he was reinstated to the 23-man squad. He was chosen to start in the group games.

2010 FIFA World Cup

Boulahrouz was included in the preliminary squad for the 2010 FIFA World Cup in South Africa. On 27 May 2010, coach Bert van Marwijk announced that Boulahrouz would be part of the final 23-man squad. Boulahrouz started in the Netherlands' last group match on 24 June, a 2–1 win over Cameroon, in place of Gregory van der Wiel. He also played in the semi-final match against Uruguay.

Goalkeeper and international teammate Edwin van der Sar said of Boulahrouz "He is an important defender, but he is also the man to lift spirits within the squad. He is the sort of guy you need around during long evenings at training camp." Former Dutch centre-back Jaap Stam said that Boulahrouz could become his successor.

Boulahrouz was born in Maassluis, Netherlands to a family of Moroccan descent. He has eight siblings. As a youngster he went to the youth academies of Ajax and Haarlem. When he was sixteen his father died and he had to take responsibility for his family. In December 2006, he married Sabia Thele. While Boulahrouz was in Switzerland preparing for the Euro 2008 quarter finals against Russia, his then wife Sabia gave birth to a prematurely born daughter Anissa who died in a Lausanne hospital. He opted to play against Russia a few days later, during which the Dutch team wore black armbands in his daughter's memory. The couple has a second daughter, Amaya (born March 2010) and a son, Daamin (born 30 January 2011). In January 2013 the couple announced their separation.