Premiership table-toppers Bath take on La Rochelle, who won the tournament in 2022 and 2023, in Friday evening’s tantalising opener for the 30th edition of the Investec Champions Cup.
Toulouse, who lifted the first title in 1996, also won the most recent edition, beating Leinster in extra-time at Tottenham Stadium in May.
Led by star scrum-half Antoine Dupont, Toulouse will lead the French charge once again as Top 14 champions and current early-season leaders.
But they are far from the only cross-Channel contenders.
An exciting Bordeaux-Begles side, including France wingers Louis Bielle-Biarrey and Damian Penaud, will fancy their chances of making the semi-finals for the first time, while Clermont Auvergne and Toulon arrive with heavyweight European pedigree behind them.
The French game has been supplemented with a crop of England stars, who are ineligible for national team selection under Rugby Football Union rules.
European action offers France-based players their best chance of impressing British and Irish Lions head coach Andy Farrell before the tour of Australia in the summer.
Former captain Owen Farrell and Henry Arundell are playing at Racing 92 under England’s World Cup 2015 coach Stuart Lancaster, Kyle Sinckler and Lewis Ludlam play at Toulon, and flanker Jack Willis is at Toulouse – a side former England wing Chris Ashton says are difficult to look past.
“Toulouse are so consistent and have an unbelievable squad,” Ashton told BBC Rugby Union Weekly.
“They always seem to be first or second in their league and always seem to be in the semi-final or final of the European Cup.”
Speaking on Rugby Union Weekly, BBC rugby correspondent Chris Jones added: “We could talk forever about possible favourites and both end up backing Toulouse.”
Leinster have added a superstar of their own. All Black centre Jordie Barrett, who briefly lived in County Meath as a child, has returned to the province, adding some stardust to a squad that already includes Ireland mainstays Caelan Doris, Hugo Keenan and James Ryan.
Could he be the signing that enables them to take the four-time champions final step once more, after finishing as runners-up in four of the past six finals?
Exeter Chiefs were the last English side to win the competition in 2020 but Harlequins and eventual Premiership champions Northampton both reached the semi-finals last year.
Bath raise the curtain against European heavyweights La Rochelle but the Premiership club, and their neighbours Bristol, could lead the way this year after their impressive starts in their domestic league.
South Africa’s sides have played in the tournament for the past two seasons, adding quality on the pitch and some long-haul logistical challenges off it.
Siya Kolisi’s short-lived stint at Racing 92 came to an end in September, with the 33-year-old Springbok captain linking up with international team-mates Eben Etzebeth, Ox Nche and Makazole Mapimpi at the Sharks.
Ashton said: “The squad Sharks have could steamroller most teams. If they decide to take it on, they could get to the final with ease.”
Jones added: “It’s hard to back a South African team to win it because of the travel issue.”
Glasgow, Scotland’s sole representatives, made the trip to South Africa last season to beat the Bulls and claimed a sensational United Rugby Championship crown.
After an impressive start to this year’s URC and a clutch of Scotland internationals eager to make their case to Farrell, few will fancy taking them on in the knockout stages.
“Glasgow have to be taken seriously given what they did in the URC, winning in Munster and then the following week getting on a flight and winning in Pretoria against the Bulls,” said Jones.
For the first time in the tournament’s history though, there will be no Welsh representation, in another blow to the nation’s pride.
