Arsenal saw William Gallas, Sol Campbell, Philippe Senderos and Mikael Silvestre leave the club in the summer of 2010, and in typical Arsene Wenger style, the manager turned to an unheralded Frenchman of whom little was known to solve his defensive problems, with Koscielny joining the club for a reported £10 million from Lorient.
If the price seemed excessive for a player who had spent just one season playing in the French top-flight, reassurrance could be found in the fact that Koscielny was the 19th French player signed by Wenger, and his track record in that regard is fairly impressive. The defender produced an encouraging performance in the Emirates Cup soon after his arrival to suggest that he would strike up a productive partnership with Thomas Vermaelen.
Koscielny's ascent to the top of European football has not been a conventional one. After beginning his career with Guingamp, he was allowed to join Tours in the third tier of the French league in 2007 and enjoyed promotion with his new side before being named in the Ligue 2 Team of the Season the following campaign.
Lorient signed him for around €1.7 million in the summer of 2009 and he quickly established himself as one of the most promising defenders in the top-flight, attracting the attentions of Wenger and Arsenal. Things didn't really go according to plan in his first season as questions were raised about his ability to lead the Gunners' backline in the absence of first-choice centre-back Thomas Vermaelen, but Koscielny proved his worth with an excellent second year in North London.
Strengths: Koscielny is a quick-thinking defender who positions himself well and shows good anticipation of danger. He also has aerial presence despite a lack of height and is a strong tackler.
Weaknesses: His decision making has been questionable at times; he showed a propensity to give away penalties in 2010-11.
Career high: Going from the French second flight to one of Europe's elite clubs in the space of 12 months.
Career low: His mix-up with Wojciech Szczesny cost Arsenal the Carling Cup final against Birmingham and the opportunity to end the Gunners' six-year trophy drought.
Style: Aggressive, uncompromising, energetic.
Quotes: "I don't believe any French player would have refused to come and play for Arsenal. It took me four years to go from the bench of Ligue 2 to Arsenal so it is a great achievement. I have been on the crest of a wave for the last few years, but it is just the beginning. I haven't proved anything yet. Arsenal is a reference for football." Laurent Koscielny, July 2010.
Trivia: Koscielny was sent off during the 2009-10 season for a challenge on Bordeaux striker, and now Arsenal team-mate, Marouane Chamakh.