The Blues take our European campaign to a Swiss border city to face fresh opponents. Club historian Rick Glanvill and club statistician Paul Dutton set the semi-final scene…
Chelsea are about to play the 12th semi-final in 55 years of European campaigning. It's our 45th time in the last four of a major competition since 1905.
Basel have never previously reached a UEFA semi-final. Their best effort to date was making the European Cup quarter-final in 1973/74 when they were beaten 6-5 on aggregate by Celtic.
All four of this season's Europa League semi-finalists began their 2012/13 European campaigns in the Champions League. Basel began way back in mid-July against Flora of Estonia in the second qualifying round. Fenerbahçe joined at the third qualifying round stage, while Chelsea and Benfica started in the Champions League in the group stage.
In all it's our 18th semi-final in all competitions since the owner bought Chelsea.
We remain champions of Europe until the trophy is lifted by another team at Wembley on 25 May. Given that the Europa League takes place on 15 May the Blues could conceivably hold both UEFA titles at the same time for 10 days.
There is, as any study of Basel's progress to this stage shows, a long way to go before that can be considered. Murat Hakin's side are three times Swiss Super League champions and have overcome Zenit St Petersburg and Tottenham Hotspur (pictured below) en route to meeting Britain's final flag-bearers.
'One team in Europe' is more than mere crowing from the Chelsea supporters, it's also a pointer to the financial and practical advantages of making the latter stages of UEFA competitions.
England's last survivors - for the second season running - stand to benefit in a number of ways, not least the Europa League's financial rewards.
The prize money for Round of 32 is €200,000, the Round of 16 €350,000, the quarter-finals €450,000, and semi-final is €1m. Runners-up in the final stand to gain an extra €2.5m and the winners pocket €5m.
More matches played than our rivals also means a greater share of the English pool of TV money. The bonus to a club rises incrementally each round they progress. One pot (€60m last season) is split between the national associations represented, based on media revenue value (of which England is highest), then split equally between clubs from that country and matches played. A further stash (€30m last year) is allocated on a round by round basis.
With Spurs and Newcastle out, Chelsea's slice of the pool money increases. These are significant funds.
Equally important, extra merit points accrued in the extra matches enhances the Blues' UEFA coefficient - crucial to being top seeds in the group stage draws should we qualify for European competition next season and in the future.
Basel reached the last four by beating 10-man Tottenham on penalties after a 4-4 aggregate tie. Brad Friedel, preferred in goal to Hugo Lloris, was at fault on both Basel goals.
FCB like to consider themselves the little brother of the FCB we beat in last year's Champions League final, Bayern. Their stadium is small and atmospheric - 'English style' as they say over there.
It does not seem 13 years since we last played in Switzerland - a UEFA Cup match against St Gallen in Zurich that mostly evokes bad memories. (You can read about it via the We Have History tab.)
However, we travel in hope of a result at St Jakob-Park that is the platform for success on the Fulham Road next Thursday.
On the other side of the draw, Fenerbahçe are also semi-final novices in Europe, although they reached the last eight of the Champions League with Zico in charge five seasons ago - before losing out to Chelsea 3-2 on aggregate.
Benfica, beaten 3-1 at that same stage by the Blues last season, won the European Cup in their heyday of the early 1960s. They have reached six UEFA finals since then and lost them all.
Tonight's semi-final Europa League ties
Basel v Chelsea 8.05pm
Fenerbahçe v Benfica 8.05pm
Our penalty at Anfield was our 17th awarded this season which is a new club record, beating the previous 16 set in 1988/89.
Click on tabs above for more briefing.
WE HAVE HISTORY
This is our first ever competitive game against Basel. Some sources suggest an extra match against a combined Basel/Grasshoppers side was added to the schedule for a Switzerland tour at the end of the 1945/46 season, Chelsea winning the match 3-2.
Our famous striker Tommy Lawton stayed for a short coaching tour of the country, taking in Friburg, Martigny and Geneva.
A more direct comparison is with our visit to Zurich to play St Gallen in 2000 shortly after the controversial sacking of manager Gianluca Vialli.
The away leg was new boss Claudio Ranieri's second match in charge as Graham Rix had stepped up to handle the first two games, a 0-2 home defeat by Leicester preceded by the first leg against the Swiss.
That was not one of the best European nights at the Bridge. Two days after the sacking, everyone from crowd to players was on edge.
Fans loudly voiced their support for the former manager as 'Vialli! Vialli!' regularly rang out around a half-full stadium. (This would continue long into the management of Ranieri.)
Even Frank Leboeuf was initially booed, perceived to have played a role in the Italian's ousting. However his would be one of the few classy performances as Chelsea laboured to a 1-0 win through Christian Panucci's 25th-minute goal.
Ranieri was unknown to Blues fans and one of his more minor contributions to the club's history was to hand the infamously unused Winston Bogarde his debut at Old Trafford (a strange 3-3 draw) and first start in Zurich.
The trip to Switzerland would be a disastrous one for the only Chelsea player born there, Roberto Di Matteo. Half an hour into the game the Italy international emerged after a challenge by Daniel Imhof in obvious agony.
Di Matteo was stretchered off with multiple bone fractures and soft tissue damage to his leg and would never play again.
By then a subdued, tinkered-with Chelsea were a goal down and minutes later it would be two - the hapless Bogarde at fault on both occasions.
Ranieri switched things round from the starting 4-3-3 at half-time, handing Georgian forward Rati Aleksidze his debut in place of right-back Panucci.
Tore Andre Flo dropped, surprisingly, to right midfield before making way for Eidur Gudjohnsen.
Chelsea made a better fist of the second half, but Gianfranco Zola's fierce drive, Flo's close-range miss and Aleksidze's striking of the bar were the closest the Blues came to a crucial away goal.
The Swiss, watched by tennis star and St Gallen fan Martina Hingis, won 2-1 on aggregate.
Chelsea's biggest away win in Europe
Jeunesse Hautcharage 0-8 Chelsea - 15/09/1971 - UEFA Cup Winners' Cup 1st round 1st leg
Basel's biggest home win in Europe
Basel 7-0 Folgore - 24/08/2000 - UEFA Cup qualifying round second leg
Visit again at lunchtime for part two of the Briefing.