Athletic club were founded 121 years ago, in 1898 and are one of only three teams that have never been relegated from La Liga since its inception in 1929.
The other two are as you could probably guess Real Madrid and FC Barcelona.
But Athletic Club of Bilbao are a completely different club to that of the present-day giants.
Winning La Liga on eight occasions, and holding the second highest Copa Del Rey titles, second only to Barcelona, with 24 to their name.
As they are the fourth most successful club in Spain, you’d expect them to be overflowing with foreign talent but that is simply not the case.
Instead Bilbao focus solely on home grown talent a method severely overlooked by almost every other football club across Europe’s top five leagues.
But it wasn’t always this way. Selecting English players for the first decade of their existence before that all changed in 1912 when they starting to abide by the policy of signing only players born in the Basque Country or those who had learned their football skills at a Basque club.
The Athletic Club policy of ‘Cantera’ doesn’t require a player to be ethnically Basque, a player only has to be brought up through the youth academy of a club in the Basque region.
From the top flight, these could include, Athletic themselves, Real Sociedad, Deportivo Alaves, and Eibar.
The controversial system is often associated with Basque nationalism and has been an extremely efficient form of promoting local talent but also criticised by many as a form of discrimination.
In 2019, they are the only club doing this but Real Sociedad had a similar policy in the 1960s before the foreign imports started to arrive in 1989.
They were also the last club in La Liga to list a black player in their starting line-up, when Jonas Ramalho joined the club.
The case of not having to be ‘ethnically Basque’ with players such as Iñaki Williams, who was born in the Basque country but has African decent considered eligible.
Williams also became Athletics’ first black goal scorer in 2015.
Manchester City defender Aymeric Laporte played for Bilbao between 2012 and 2018 was born in France but of Basque heritage.
Athletic Club have a habit of selling their best players for significant transfer fees. Generating a combined €140m by selling Aymeric Laporte and Kepa Arrizabalaga to premier league clubs.
The problem with this is that, after those players have gone, regardless of the money involved the club will often stay out of the market and instead invest the funds into unearthing the next big thing in the Basque region.
But what happens when they simply just aren’t there, for the time being at least. Where do they go, to replace the quality that has been sold?
That makes progress in La Liga harder to sustain, taking this season for example, Bilbao have flirted with relegation and are likely to be in a relegation dog fight for the rest of the current campaign.
In November they looked in really bad shape after winning just one of their opening 13 La Liga games.
But have managed to climb out of the relegation zone after a run of results which has seen them go un-beaten in their last six games and losing only once since the start of December.
Despite currently occupying 14th place at the time of writing, Los Leones are still just three points from Rayo Vallecano in 18th and could easily be dragged back into the drop zone.
With tough home games coming up against both Real Betis and FC Barcelona, Gaizka Garitano’s side are far from safe.
So, with the treat being very real, should the Basque club ignore their self-imposed recruitment strategy as the transfer window comes to a close to recruit the quality they require?
Athletic have already added to Ibai Gómez to their ranks from Deportivo Alaves, adding some much-needed attacking depth.
But you get the feeling that more faces will need to arrive if they are to remain as one of the few to never be relegated.
Setting the policy, to one side for this transfer window only would offer them far more options and could be the difference between staying in the league or being relegated for the first time.