Sol Campbell and Rio Ferdinand. Ferdinand and John Terry. Terry and Joleon Lescott.
England have consistently and frequently in their most recent past been able to partner two solid, strong central defenders in their national team as they qualify for and compete in major tournaments.
Stretching back even further, the likes of Tony Adams, Gareth Southgate, Terry Butcher and Des Walker all provided great quality in their time, but the most recent of those partnerships has been ended now and it is up to manager Roy Hodgson to find the best new one at his disposal.
England have always been lacking in one area or another going into major tournaments over the past 20 years—not enough technical players, no decent left winger, too many strikers injured or unavailable—but rarely has the centre of defence come under this kind of scrutiny.
Even when a first-choice centre back was missing there was usually an equally able replacement ready and waiting; Jamie Carragher and Ledley King, for example, battling for a spot in Euro 2004 following John Terry's short-term injury.
With former captain John Terry gone from the international scene and Rio Ferdinand well out of the picture, only one relatively experienced central defender remains in Joleon Lescott.
As a Premier League winner from last season and a semi-regular starter in Roberto Mancini's table-toppers this season (Lescott has started six of City's 12 league games) it would perhaps be a fair assumption that he would make up one half of Hodgson's defensive duo when available, but Everton's Phil Jagielka makes a strong case to usurp Lescott at present with form and playing time in his favour.
Internationally, Lescott has won 24 caps, Jagielka 16. Neither, then, are particularly blessed with vast experience at this level but have both played a huge number of top flight games and are 30 years old. Technically speaking, they are both strong in the air, unafraid of putting in challenges and blocks and are by and large "defensive" defenders.
They take care of business first.
Alongside them, England need someone rather younger, with a little more pace and the technical ability to be comfortable on the ball.
Roy Hodgson's sides are never going to play out from the back and recycle possession constantly in deep areas, but to think that the defenders can consistently hit the wingers 50, 60 yards up the pitch at the top level and the team be successful is naive in the extreme.
In time, any of Chris Smalling, Phil Jones or Steven Caulker could take over this role, but inexperience and fitness issues mean they are unlikely to do so for the remainder of the World Cup 2014 qualifiers or for the main event itself—should England get there and a centre-back pairing establish itself in doing so.
Gary Cahill then has both the technical attributes, the experience of playing for a top side and a fair starting point of international acumen garnered in his 13 caps to date, to be the obvious choice for that role.
He's a good defender. Whether he can become a great, as Campbell, Butcher, Terry and co. were in their prime is still up for debate.
At 26 years old Cahill should now be coming into his prime where positional ability and reading of the game combine with his peak athletic years, and yet he is still not trusted as an undisputed first choice for his club.
Cahill's prowess at the other end of the pitch scoring goals is also not to be underestimated.
He has a new manager now, one who works tirelessly with his defenders to position themselves correctly and applies a very, very solid defensive strategy off set pieces and who has, previously, started life at a new club by pushing the defensive line higher up the pitch.
Whether Rafa Benitez attempts to do that at Chelsea remains to be seen, but Cahill can and must improve further if he is to become an integral part of the England defence.
There is no doubt that, though he has talent, Cahill also possesses certain limitations. A certain tendency to being caught on the ball at times, a propensity to fail to track runners behind him and occasionally an openness between himself and his fellow centre-half—these are all issues, at least in part, because Cahill does not start regularly enough.
They are also issues which will get him, and England as a team, found out against top opposition.
England have only these three senior defenders at present. Lescott, Jagielka and Cahill.
One from either of the former two will provide a solid, "all-English" approach to defending when they are in form, but it is in partnering Cahill where Roy Hodgson's teams may live or die.
Cahill has the ability to prove himself further than he has already done so and can, under the tutelage of Benitez and Hodgson, become a much better all-round defender who would, in turn, make England a much better side at the back.
But if he fails to do so then England look extremely short of top-drawer centre-backs right now—and regardless of attacking talent, that will absolutely cost the nation if and when they come up against the world's best offensive players at World Cup 2014.
Stats from WhoScored.com and EPLIndex.com