Over the past 24 hours or so, thousands of Celtic fans have descended on Lisbon.
A city to which their club will forever be linked in the most romantic terms, making the journey here is a rite of passage.
Especially with this season marking the 60th anniversary of the Lisbon Lions, it is a pilgrimage to a place of spiritual and emotional significance, one which is woven into the fabric of the club.
Bathed in the most glorious sunshine, the old Estadio Nacional felt like it had come alive yesterday afternoon.
The trees and shrubbery which surround the stadium eventually cast long shadows over the pitch. Up on the steps, the silhouette of Billy McNeill lifting the European Cup would have been visible to many.
One of the tour guides, Carlos, was doing his best to bridge the language barrier between Portuguese and Glaswegian.
Celtic captain Billy McNeill with the European Cup in 1967
Celtic celebrate Stevie Chalmers’ goal in the 1967 European Cup win over Inter Milan in Lisbon
For the many thousands of Celtic fans who have made this journey over the years, they are united by the memory and wider resonance of that victory over Inter Milan.
The 59 years which have passed have only burnished its romance. An exhibition titled ‘From Glasgow to Glory,’ occupies the tunnel of the Estadio Nacional itself.
The hours have been extended this week so that the travelling support can walk the same path that Jock Stein and his players once took.
They will stand where McNeill stood and they will feel the weight of what was achieved. For many, it is a necessary communion with the club’s finest hour.
Yet, truthfully, the Celtic team that have arrived here under Martin O’Neill for a Europa League clash with Benfica tonight is a million miles removed from those former glories. The contrast is almost cruel.
Earlier this week, there was a line from Celtic defender Liam Scales which referenced the Europa League victory away to Feyenoord last season as an example of winning against the odds.
Turning back the clock to that night in Rotterdam last November, where Celtic would claim a 3-1 victory, the words of O’Neill are worth revisiting.
Speaking pre-match, as he prepared to hand over the reins to Wilfried Nancy a few days later, O’Neill was asked to give his thoughts on what it might take for Celtic to get back competing at the top level again.
‘Jock Stein said it – European football is where Celtic should be,’ said O’Neill in his media conference deep in the bowels of De Kuip.
‘But at this minute it’s a struggle for us. Recruitment is important. In the next couple of years, Celtic will come again in European football.’
The chance to lead a revival in Europe and for Celtic to ‘come again’, in O’Neill’s words, were unquestionably a major factor in his decision to stay and have another crack at it this season.
The Celtic team are pictured with the European Cup in 1967
Celtic return to a hero’s welcome at Parkhead after becoming the first British team to win the European Cup
However, right now, the painful reality is that Celtic look further away than ever before in terms of being able to make a tangible impact in European competition.
Only Stein stands above O’Neill in the pantheon of Celtic’s all-time greatest managers. Yet, for all the residual affection that is attached to his name, his team have lost their way.
The scar tissue from that Champions League collapse against LASK Linz, where Celtic blew a four-goal lead, still runs deep.
A torrid week in September left Celtic with three consecutive defeats: twice to Rangers and once, embarrassingly, 3-1 at home to Ferencvaros in the opening match of this Europa League league phase.
O’Neill spoke afterwards of reflection and of the possibility that it might be time to ‘wrap it up’. The international break allowed cooler and calmer counsel to prevail.
He has chosen to stay. The club, for its part, has offered public support. Yet the doubts that surround the side have not evaporated on the basis of a 2-0 victory over Motherwell last weekend.
If Cameron Carter-Vickers is once again absent through injury, Celtic could line up with a back four tonight of Colby Donovan, Liam Scales, Dane Murray and Kieran Tierney.
The fact that they spent good money at the top end of the pitch in the summer is irrelevant in the respect that any team is only as strong as their weakest links.
Going up against a team of Benfica’s quality with the likes of Murray and Scales at centre-back is why so many Celtic fans who hadn’t travelled to Lisbon will watch this match through the cracks of their fingers from behind the sofa.
Digging through some of the numbers, few would blame them. Celtic have kept just two clean sheets in their last 29 Europa League matches.
Celtic walk out in the Portuguese son for their mdate with destiny almost 60 years ago
Benfica at the Estadio da Luz are a formidable prospect. Just last season, whilst under the command of Jose Mourinho, they beat Real Madrid 4-2 in the Champions League here in Lisbon.
Mourinho left to take charge of Madrid for a second time in the summer and has since been replaced by his Portuguese compatriot Marco Silva.
During his time in the English Premier League with the likes of Fulham, Everton, Watford and Hull City, it often felt like Silva divided opinion.
But he has made a good start with Benfica. Silva’s side have won nine of their last ten matches across all competitions. Their only loss in their last 14 matches came recently against Porto.
A couple of months ago, Wouter Vrancken’s Hearts were battered 6-1 in a Europa League qualifier here in Lisbon.
Vangelis Pavlidis was among the goalscorers that night and the Greek striker has been in electric form with 14 goals in 14 matches so far this season.
Celtic fans probably hoped to see a similar sort of return from Kasper Hogh after he joined for a club record fee of £11million in the summer.
But Hogh has struggled to justify that price tag. He looks to be a striker short on confidence and lacking the capabilities to lead the line for Celtic.
If O’Neill can start to get more of a tune out of Hogh, especially in these big games, it would go a long way to turning things around. A resurgent Hearts at Parkhead on Sunday will be another major test.
Celtic manager Jock Stein lifts the European Cup
O’Neill’s predicament is not merely one of results. There is a growing sense of toxicity between the club’s support and its ownership.
Protests directed at principal shareholder Dermot Desmond have brought the whole thing to the surface again. Desmond’s subsequent response in a club statement had the effect of pouring petrol on the flames.
O’Neill has spoken of the rift as ‘really sad’ and insisted that such matters lie beyond his control. He is right, of course.
A manager can only deal with the players in front of him and the matches they face. Yet the broader context of discontent cannot be ignored.
The more that O’Neill chooses to align himself with Desmond by claiming that these protests ‘are not Celtic’, the more he risks alienating himself from the fanbase and tarnishing his legacy.
In a way, he can’t win. In a city which once offered the purest reflection of Celtic’s identity as a club, what now stares back at them is a pale imitation.
The Lisbon Lions did not merely win a European Cup in this city. They created a legacy that continues to define what this club aspires to be.
The present side are a million miles removed from living up to it. What happens against Benfica tonight could well highlight that chasm with painful clarity.
At the Estadio da Luz, or the Stadium of Light in English, it is O’Neill and Celtic who are still trying to fight their way through the darkness of European irrelevance.
