Tens of thousands of Rangers fans are in Seville for one of the biggest matches in the club’s history.
Police expected up to 100,000 supporters of the Glasgow team to travel to the Spanish city for the Europa League final.
They were joined by 50,000 fans of German side Eintracht Frankfurt.
The vast majority of those who have travelled did not have tickets for the game in the 42,700-capacity Estadio Ramon Sanchez Pizjuan.
Only 9,500 tickets were originally sold to Rangers fans, although more are believed to have been made available in recent days.
Ticketless Rangers fans are able to watch the match at the 57,000-capacity Estadio La Cartuja in the north of the city – where Celtic lost the 2003 Uefa Cup final to Porto.
Former Rangers captain John Greig, who led the team to victory in the European Cup Winners’ Cup Final in Barcelona in 1972, wrote an open letter to fans ahead of the final urging them to be “ambassadors” and show the “absolute best” of the club.
He added: “To see Rangers in a European final is something many of us thought would not be possible again, and I’ve been so taken by the incredible lengths you are going to in order to reach Seville to back the team out there.
“It is vital that we all act responsibly and remember the values that this institution stands for.”
Seville Police said they were prepared for large numbers of supporters in the city for the match – which kicked off at 20:00 – with about 5,000 officers on duty.
Many bars in Seville are closed on Wednesday, but fans are able to watch the game on big screens around the city.
More than 400 flights arrived in the city on Tuesday, with a similar number – including 16 charter flights from Glasgow Airport – expected on Wednesday, with trains and coaches travelling to the city also full.
There was a carnival atmosphere on the streets ahead of the match, with the BBC’s Lorna Gordon saying she had seen lots of good-natured exchanges between the two sets of fans.
She added: “The great and the good from Rangers are urging fans to be ambassadors and do their absolute best for the club – and they are”.
Rangers fans have travelled from across the globe to watch the final, with some travelling from as far as Australia despite not having tickets.
Brian, originally from Nairn, spent 40 hours travelling to Seville from Sydney. He bought a match ticket on Tuesday for 1,600 euros (about £1,350) and reckons he has spent about £5,000 on the trip so far.
“And that doesn’t include any drinks, so you can double that!” he told BBC Scotland. “It is money well spent. I didn’t travel from Australia not to see the game.
“I am 54, I have been a Rangers fan my whole life and will probably never see this again in my lifetime.”
Among those lucky enough to have tickets for the game were Zac Smith, 11, his 10-year-old brother Tom and their twin 14-year-old cousins Jack and Adam – the grandsons of legendary Rangers manager Walter Smith, who died last year.
All four are too young to remember their papa leading the club into their last final in 2008, with Zac predicting a 2-0 win this time around.
He added: “Rangers have made it this far in the tournament playing amazing teams and I think Rangers will beat Frankfurt.
“It has been amazing. I’ve never experienced this with Rangers – it’s mind blowing.
“Obviously my papa made it to the final and didn’t win it – we’re trying to make up for that today”.
The boys only found out after school last Friday that they would be going to the match, with Jack saying his grandfather would have been “having a blast” among the Rangers fans.
By Tom English, BBC Scotland in Seville
They’ve come in from every conceivable direction. The multiple charters out of Glasgow are the least of it.
Some have scrambled to Seville via Marrakesh in Morocco, others have gone Glasgow-Gatwick-Bilbao-Seville, Glasgow-Luton-Lisbon-Seville, Edinburgh-Bergamo-Milan-Madrid-Seville.
There are tales of expats coming up from the Southern Hemisphere. The Rainbow Hot Air Balloon company took calls from folk wondering if they could book something to get them to Spain. The owners thought it was a wind-up at first. It wasn’t.
There are hundreds if not thousands of stories knocking about and they will become legend if Rangers beat Eintracht Frankfurt on Wednesday night.
They’ll be passed down the generations, some real, some exaggerated or invented, but magnificent nonetheless. “My granda cycled to Seville with his big mate Archie on the handlebars.”
There’s a fantastic madness to it all, a uniqueness. This is Rangers’ second European final in half a century. Who knows when they are going to be in another one and how many of their fans who have made this trip will be alive to see it.
Rangers were last in a European final in 2008, when they lost 2-0 to Russian side Zenit St Petersburg in the Uefa Cup final in Manchester.
They have now reached five finals, which is as many as every other Scottish side combined.
The Scottish club has already knocked out German giants Borussia Dortmund and RB Leipzig on their route to the final, and will be looking to add Eintracht Frankfurt to that list as they attempt to win a major European trophy for the second time in their history.
This will be Eintracht’s third European final. They lost in the 1960 European Cup against Real Madrid at Hampden before beating Borussia Monchengladbach to lift the 1980 Uefa Cup.
The German side are unbeaten in this season’s tournament, and have defeated Barcelona and West Ham United in previous rounds.
Clifford Stott, a professor in crowd psychology at Keele University, told BBC Radio Scotland there would be an added challenge for the police in Seville because the largest crowds would be at neighbouring stadiums where the match is being shown on big screens.
Prof Stott said that Spanish policing could be “quite provocative and very heavy handed” but officers would need to address “the legitimate ambitions of the vast bulk of supporters coming across” rather than just looking out for any troublemakers.
Five Eintracht Frankfurt fans were arrested for disorder on Tuesday evening, with one Rangers fan treated for a head injury – but police said there were no serious injuries.
Meanwhile, large numbers of Rangers fans who have not travelled to Spain are expected to gather in the centre of Glasgow on Wednesday evening.
Police Scotland said they would do everything they could to reduce disruption, with the city council saying it had removed memorial benches in George Square, some of which were damaged last year during celebrations of Rangers’ Scottish Premiership title triumph last year.