On July 3, 2001, Arsenal completed the shock signing of Sol Campbell from Tottenham Hotspur. It was a huge coup: not only had the Gunners stolen Spurs' best player and captain, but they had managed to do so on a free transfer.
Campbell went on to become a mainstay of the Arsenal defence, winning two Premier League titles before leaving the club in 2006. In this piece, Bleacher Report asks where Campbell ranks among Arsenal's best centre-backs of the last 25 years, pitting the former England international against some of the best defenders to grace Highbury and subsequently the Emirates Stadium.
The assessment is about more than just the individual trophy haul. The best centre-halves are great leaders and organisers, and some of those intangibles are factored into this analysis.
Read on to discover where Campbell sits in such illustrious company.
7. Per Mertesacker
Some fans may be surprised to see Per Mertesacker make this list. However, since joining the club in the turbulent summer of 2011, the giant German has quietly established himself as a significant figure at the club.
When he arrived, Arsenal lacked leadership and personality. Mertesacker immediately established himself as an authoritative figure in the dressing-room—in fact, it became inevitable that he would eventually succeed Mikel Arteta as club captain.
On the field, his adaptation took some time. A chronic lack of pace threatened to render him unsuitable for the demands of the Premier League, but his positional sense and tactical intelligence allowed him to adapt sufficiently to form a fantastic partnership with Laurent Koscielny.
Mertesacker's most recent Arsenal appearance came in the 2017 FA Cup final. Starting his first match of the season in the final game of the campaign, he produced a man-of-the-match performance to help Arsenal claim the trophy, thus cementing his role in Gunners folklore.
6. Kolo Toure
When he first broke into the Arsenal team, Ivorian Kolo Toure was not even regarded as a centre-half. His first few appearances came on the flanks, and his boundless energy and dribbling ability seemed to point towards a career in midfield.
However, Arsene Wenger saw in Toure the potential for an athletic centre-half. Deployed in defence, his remarkable physical gifts made him a nightmare for any centre-forward to face.
Toure was a good footballer, too, and he made up for Campbell's technical shortcomings with his willingness to carry the ball up the field and instigate Arsenal's intricate passing moves.
Any defender who can go through an entire Premier League season unbeaten deserves to make it on to this list. The reason Toure doesn't figure higher is that he was somewhat dependent on the quality of his partner—once Campbell left Arsenal, he never quite looked the same player.
5. Martin Keown
Martin Keown's passion and aggression made him a cult hero at Arsenal—but he was also a truly outstanding centre-half.
His real strength was his man-marking ability. Keown was an expert when it came to denying the striker a yard's space—or a moment's peace. Former Aston Villa striker Tony Cascarino told The Times (h/t Goal):
"Martin Keown was like a rash for Arsenal, he just used to stay with people, no matter where they went on the pitch. He was brilliant at it."
George Graham frequently made use of Keown's ability to shut down the opposition's star player, particularly in European ties.
However, under Wenger, Keown showed he was also a capable footballer, adapting to form effective partnerships with the likes of Tony Adams and Campbell.
4. Steve Bould
It's difficult to choose between Keown and Steve Bould. The two were locked in close competition to partner Adams throughout the 1990s, until Bruce Rioch decided to utilise them both in a back three that was later inherited by Wenger.
Keown was quicker and more aggressive than Bould, but the former Stoke City man made up for that with his impeccable reading of the game. Bould emanated an unflinching sense of calm. He barely seemed to break a sweat, elegantly mopping up at the back and helping to marshal the most efficient offside trap in English football.
These days, Bould can be found next to Wenger in the dugout as Arsenal's assistant manager. Unfortunately, he has not yet been able to instil the same focus and discipline into the current Arsenal defence.
3. Laurent Koscielny
Koscielny has not lifted the Premier League trophy with Arsenal, but the fact that he has still forced his way into the top three is testament to his remarkable quality as a defender.
The 31-year-old would comfortably have graced the best Arsenal teams of the past 25 years. Perhaps his most eye-catching quality is his pace. Strikers rarely win a foot-race with the Frenchman, whose acceleration is matched by his aggression.
That can sometimes lead to costly errors. Koscielny's determination to win the ball occasionally boils over into recklessness, and it's these infrequent aberrations that prevent him from figuring higher on this list.
Nevertheless, he remains an outstanding centre-half who has arguably been let down by some of the defenders he's been paired with throughout his Arsenal career.
2. Sol Campbell
There can be no doubt that Campbell proved to be one of the greatest signings in Arsenal's history. In just five years at Highbury, he won two Premier League titles and three FA Cups.
His arrived at a time when Arsenal's defence was undergoing a process of evolution. The likes of Adams, Bould and Keown were gradually being phased out, and Campbell was charged with leading a new generation of defenders.
In that respect, the Invincibles campaign of 2003/04 was arguably his greatest triumph. A new-look defence of Campbell, Toure, Ashley Cole and Lauren managed to navigate the entire season unbeaten.
The one thing missing from Campbell's time with Arsenal was the Champions League trophy. Campbell scored in the final in 2006 in what would prove to be his final game for the club. However, Barcelona's late comeback meant he would never lift Europe's biggest prize.
1. Tony Adams
Only one man could possibly pip Campbell to the title of being Arsenal's greatest centre-half in modern history: Mr. Arsenal himself.
Adams was a one-club man whose Arsenal career spanned almost 20 years. In that time, he won four league titles, three FA Cups, two League Cups and a European Cup Winners' Cup.
His iconic status is made plain by the fact that a statue of the towering centre-half stands outside the Emirates Stadium. Until Campbell is cast in bronze, he can't quite compete with the legendary Adams.
James McNicholas is Bleacher Report's lead Arsenal correspondent and follows the club from a London base.