Athletic Club Bilbao is without question one of the most successful clubs in Spanish football history. The Basques have won La Liga eight times and have also been historically mesmerizing in the Copa del Rey winning it 24 times and finishing as runners-up on 14 occasions.
Athletic also joins the special company of Barcelona and Real Madrid as the only three clubs to have never been relegated from La Liga.
The history of Los Leones is a deep and rich one. The club has enjoyed golden ages in the 1910s, 1930s, 1950s and the 1980s. But nothing compares to the legends that have worn the Txurigorri shirt.
Spanish football treasures such as Pichichi and Telmo Zarra spent their entire careers at Athletic. More recent stars such as Joseba Etxeberria, Andoni Goikoetxea and Iribar have also graced the San Mames over the years fully devoted to the club.
The Basque-only policy has also yielded one of the most successful youth systems in the football world in La Cantera de Lezama. The policy has also helped the club remain absolutely debt-free while the rest of Spanish clubs suffer financial turmoil.
Truly Athletic Club Bilbao is a gem of La Liga and historically one of the greats. But the success of Los Leones has been a thing of the past for far too long.
The last major trophies won by the club took place in 1984 when Athletic won the La Liga trophy as well as the Copa del Rey while they also lifted the Spanish Supercup at the beginning of the 1984 season. That was a long time ago.
Since 1984 Athletic Club has failed to lift any silverware despite having incredible squads over the past 3 decades.
Athletic reached both the Copa del Rey and Europa League finals two seasons ago, but were unable to win either competition.
But things are changing for the Basque giants. At the turn of the new year, Athletic are sitting in fourth place in the La Liga table trailing Real Madrid by only eight points while also being undefeated at home this season.
Many have been asking what has caused this return to success. Well, it all began a few months ago.
The San Mames stadium which was the oldest in Spain had seen its last game and the new San Mames was being constructed to take its place. Athletic Club had called La Catedral home since 1913 and fans hated to see it go.
During the summer while the new stadium was under construction, former manager Ernesto Valverde returned to Athletic to take over for Marcelo Bielsa who had parted ways with the club after last year's disastrous season.
It was difficult to watch Bielsa leave the club after the success he had brought, but fans all across the Basque Country were excited to see Valverde return.
The Basque Valverde spent the bulk of his playing career at Athletic Club and has become one of the best coaches in the game today. His return to the club was seen as a homecoming and fans were thrilled about what he was going to do.
Changes were immediately made. Several youth stars left on loan while the excess was trimmed away. Valverde brought in five new players to the squad as well, all of whom had grown up in the club's youth system.
The 49-year-old manager was re-uniting the club and needed to immediately make an impact following the exits of Fernando Llorente and Fernando Amorebieta.
In Athletic's very first game of the season they defeated Real Valladolid 2-1 and while the players were clearly getting used to a new system of play, there was a visible change.
Bielsa's former system of constant running was gone and it was clear that Valverde was bringing back Athletic's historical way of playing that consisted of constant pressure, midfield strength and attacking down the wings.
From the very first match fans could see that Athletic was returning to its roots.
On September 16, Athletic Club hosted Celta Vigo at the new San Mames. After conceding an early goal, the Lions stormed back to win the match 3-2 in one of the most entertaining football matches of the La Liga season thus far.
The feel of the new stadium, which is being referred to as the San Mames Barria or simply San Mames by fans, was odd. La Catedral was gone and it took the fans until the end of the match to get into the game the way they were used to.
Though the construction is not fully finished it is still an extremely beautiful stadium. But to the fans of Athletic, it is all about the atmosphere.
The atmosphere was different. History did not reign supreme across the stadium and thus Athletic would have to make new history.
The comeback victory over Celta Vigo showed the resilience of Athletic. The players refused to quit and the fans eventually overcame the odd feeling of being in a new stadium by roaring their chants the way Spain is used to seeing.
By the end of the match the new San Mames had not only been inaugurated, it was embraced and it was home.
In truth, a comeback victory was just the type of opening game the new stadium needed. History was already being made and Athletic ushered in their new era under Valverde in the new stadium by returning to their roots.
Los Leones spent the early part of the season winning games at home while dropping points on the road. It was the tale of two sides as inconsistency plagued Athletic, but their home form never suffered.
Athletic dropped points at home for the first time on October 6 when they drew with Valencia 1-1. But it was not a loss.
Valverde's men began to get into their rhythm under the new system after a month or so and began winning on the road as well.
With away wins against both Getafe and Malaga it was becoming clear that Athletic was a force to be reckoned with and that Valverde's system was working wonders. All the while, the new San Mames remained a fortress.
Athletic would face their toughest test of the season on December 1 as they hosted Barcelona at the undefeated fortress of the San Mames.
Going into the game Barcelona were clear favorites. But they would run into a very determined and passionate Athletic side that day that reminded everyone of the real Basque club that has been seen throughout history.
The new San Mames would remain unconquered as Athletic defeated Barcelona 1-0 and moved to fourth in the La Liga table where they stand today.
Since the victory over Barcelona, the Basques have remained undefeated at home.
The best showing thus far in the new stadium came against Celta Vigo just two weeks ago. Having lost 1-0 in the first leg of the Copa del Rey tie, Athletic needed a big win at home to advance to the next round.
Athletic Club thrashed Celta Vigo 4-0 in their most dominant performance of the season and showed the world that Los Leones have truly returned.
Valverde has led the club to its best start in over two decades and there are no signs of Athletic slowing down.
While they are not at the same level as Real Madrid, Barcelona or Atletico Madrid, Athletic Club Bilbao have returned. They have made the fourth place spot in the table their own and the scary thing is that we have still yet to see the very best from this team.
Will Athletic Club Bilbao be playing in the Champions League next season?
The second half of the La Liga season will be huge for Athletic. Their pursuit of Champions League play looks promising and you can bet that Ernesto Valverde will continue to lead the Basque club as there is still much room for improvement.
It will likely still be a while before Athletic manage take home silverware, but they are absolutely headed in the right direction. As of now the goal is playing in the Champions League.
Athletic Club has no debt, a new stadium, one of the best managers in the game who loves the club and one of the most praised youth systems in the world. Los Leones are back.
What do you think of Athletic's season thus far? Will Valverde lead Athletic to a cup win the next few years? Leave your thoughts and comments below!
* Note all club history is courtesy of the club's official website.