When Spain began their rise to world domination, in the Euro 2008 final with a 1-0 victory over Germany, there were five starters drawn from either Real Madrid or Barcelona.
Two years later and World Cup glory was secured, a 1-0 extra-time victory over Holland. Andres Iniesta struck that day, one of 10 players in the starting line-up from Spain's Big Two.
The feat was repeated in 2012, when a 4-0 win over Italy retained the European Championship crown. That day, David Silva was the only starter not from Barcelona or Real Madrid.
As Spain's power waned over the following years, the two Spanish giants have also dipped gradually in influence. The 2014 World Cup squad contained 10 of their players, and for Euro 2016 there were seven.
Yet even for the 2018 World Cup, Julen Lopetegui named a core of 10 players from those two clubs. That becomes 13 if you include fellow powerhouse Atletico Madrid.
Of the team that finished the defeat by Russia on penalties in the second round, three were from Real Madrid, four were from Barcelona, three were of Atletico Madrid's squad and one - keeper David de Gea - was from Manchester United.
Since crashing out of that tournament, the make-up of the national side changed dramatically - and immediately - as the country enter a brave new era.
In the 4-1 win over Wales in October 2018, just Sergio Ramos and Dani Ceballos represented Real Madrid, while Sergio Busquets was the only Barcelona player in the wider squad. That theme has continued.
Against Sweden last month, when Euro 2020 qualification was assured with a last-minute equaliser from Valencia's Rodrigo, not a single Real Madrid or Barcelona player remained on the pitch at full-time.
When the squad was announced for qualification matches against Malta and Romania this month, just Sergio Ramos, Dani Carvajal and Sergio Busquets remained. From Atletico Madrid, there was Alvaro Morata and Saul Niguez.
The three clubs were equally represented in the French national team, with Alphonse Areola, Raphael Varane, Clement Lenglet, Antoine Griezmann and Thomas Lemar all called up.
Of those, Ramos may be captain and have 168 caps, but he turns 34 in March and cannot resist the ageing process forever.
Team-mate Carvajal, at 27, has time on his side but has endured plenty of injury woes and there is plenty of competition at right back.
Busquets, another centurion, similarly has slowed down in recent seasons and is no longer an automatic selection for his country, while in Dutchman Frenkie de Jong his club have already moved to sign his successor.
Across the squad, the signs have been coming for a while. Of the all-conquering, free-flowing Barcelona side between 2008 and 2015, just two others, alongside Busquets, remain starters at the Nou Camp.
Gerard Pique retired from international football after the 2018 World Cup, Jordi Alba is 30 and increasingly injury-prone. Long gone are Carles Puyol, Xavi, Iniesta, David Villa and Pedro.
Faced with a vacuum in the squad, Luis Enrique - appointed following the 2018 World Cup before stepping down in June for personal reasons - and his successor Robert Moreno have looked far and wide.
There are more Villarreal players - Santi Cazorla, Pau Torres, Raul Albiol and Gerard Moreno - than from the Big Two.
Valencia contribute one player, while Real Sociedad's Mikel Oyarzabal is selected, along with Dinamo Zagreb youngster Dani Olmo.
Wolves' Adama Traore, once of Barcelona's academy, was selected, initially as a replacement for Rodrigo before being forced to withdraw through injury himself.
There are still echoes of their legacy in the current squad; striker Rodrigo and midfielder Pablo Sarabia came through Real Madrid's youth system, while Albiol made 81 La Liga appearances for the club.
Thiago Alcantara is a La Masia graduate alongside Olmo and Traore, with Paco Alcacer also a former Barcelona player.
In David de Gea, Koke, Morata and Rodri there are plenty of Atletico Madrid alumni.
However, the Spain squad has certainly never been quite as diverse from a footballing perspective, with 17 different clubs from six different countries represented.
Croatia, Italy, Spain, England, France and Germany all contribute players as Moreno spreads the net ever wider.
The coach has previously claimed this is simply the nature of the modern game - and pointed to a lack of game time for Spanish players at the top clubs.
'Football is taking us that way,' Moreno said. 'There are not many "national" players in most teams apart from Athletic [Club Bilbao], of course, and that makes it hard.
'Villarreal are the team with the most [here], think about that... I'd love to have nine players all playing in a wonderful team together; it would make things a lot easier, they would understand each other.
'But at Madrid or Barcelona, there are not many who play regularly as starters.'
Part of the problem is that neither club, nor Atletico Madrid, is producing and retaining young players like they used to.
In the current Barcelona first-team squad, there are hopes that Carles Alena, Riqui Puig and 17-year-old Ansu Fati will reach world-class level but even then they face a near impossible task to emulate their predecessors.
Real Madrid, also, have seen the fortunes of Isco wane through poor form and injury, while one-time prodigy Marco Asensio is sidelined for the season with a knee injury.
Their young prospects are, realistically, limited to Brazilian pair Rodrygo and Vinicius Jnr. They sold Morata to Chelsea and after an ill-fated spell in London the striker has earned a recall for his fine form with Atletico Madrid.
He is, however, their only contribution to the squad. Koke appears to be permanently out of favour, and beyond that there is little Spanish representation.
There is young talent coming through - as they demonstrated by winning the 2019 Under 21 Euros this summer - but it simply isn't at the big clubs any more.
Of that successful under-age side, just Jesus Vallejo and Dani Ceballos came from Real Madrid, and they have since moved on loan to Wolves and Arsenal respectively.
There were no Barcelona players in the squad, although left back Junior Firpo has since made the move from Real Betis.
It does appear that the golden generation of Spanish football is, for the moment at least, at an end as the national side tries to find new ways to thrive.