Clermont Auvergne’s defeat to Racing 92 in the Champions Cup semi-final at Stade Marcel Michelin earlier this month has denied Leinster an opportunity to do something that no other club has managed in the period under scrutiny dating back to 2000, and that is to beat the reigning European, English, French and Pro14 champions en route to winning the title.

In this season’s tournament, Leo Cullen’s team has accounted for the 2017 Aviva Premiership winners, the Exeter Chiefs, home and away; the two-time and defending European champions, Saracens; and the reigning Pro14 title holders, Scarlets, in reaching the final in Bilbao next month. Clermont are the current Top 14 champions.

The Irish province still have the not-inconsiderable task of trying to beat their Parisian opponents, who were the 2016 Champions Cup runners-up, losing to Saracens in the final. There is a hefty chunk of the period illustrated in the graphic in which a clean sweep of champions wasn’t possible simply because clubs won successive European titles.

The Leicester Tigers were European champions in 2001 and 2002 (they also won the English Premiership in those years too), Leinster in 2011 and 2012, Toulon in 2013, 2014 and 2015 and Saracens in 2016 and 2017 – nine of the 18 seasons in question. There were only four years in which a club won the Heineken Cup, as it was then, and didn’t beat either a reigning national champion or a team that would go on to claim their domestic league later that same season.

When the Northampton Saints squeezed past Munster 9-8 in the 2000 final at Twickenham, Ulster were the premier team in Europe (1999), Toulouse had won the Bouclier de Brennus the previous season, while Leicester Tigers were their English counterparts.

Celtic League The inaugural season of the Celtic League was run in the 2001-2002 season as the Leicester Tigers won their second successive Heineken Cup. They accounted for Leinster in the quarter-final, with the Irish province having won the “domestic league” at that point as the final that particular year was played in December, 2001. The Tigers therefore became the first European winners to beat a league title holder in the same season.

The first season of the Celtic League bore an uncanny resemblance to the current Pro14 structure, albeit dividing the constituents into two groups. Leinster, who topped Pool A, beat Newport and Glasgow in the knockout stages before getting the better of Munster, who headed Pool B 24-20 in the final.

In 2003 Toulouse marched through Europe to the title and in the semi-final edged past Munster 13-12; the latter were the Celtic League champions having won the title in February of that year. Wasps, under current Welsh coach Warren Gatland, became the first club to beat reigning champions in Europe, vanquishing Toulouse in the 2004 final.

Indeed, that victory stopped the French club from becoming the first to claim three European crowns in a row as Toulouse won again in 2005.

Munster’s achievement in winning the 2006 Heineken Cup could reasonably claim pre-eminence in achievement terms as they beat the Sale Sharks, winners of the English Premiership, later that season at the pool stage of the tournament and in the final at the Millennium stadium beat Biarritz Olympique, who would go on to retain the French Top 14 title.

European crown The Irish province’s second European crown in 2008 saw them dethrone European kingpins Wasps at the pool stage – the London club won the Premiership title that season – and in the final a Toulouse side, who would subsequently make up for the disappointment of losing by claiming the French Top 14 less than a month later.

Leinster were Pro12 champions when they won the first of three Heineken Cups in 2009 – the first to have that status contemporaneously as Pro12 and European winners – and in Europe beat English title holders Wasps at the pool stages and the defending champions Munster in a semi-final at Croke Park.

But it was Leinster’s second triumph in 2011, the first European crown under current Ireland coach Joe Schmidt, that perhaps offers the most persuasive argument as to the most impressive list of scalps on the way to winning a European title.

The Irish province edged past the 2010 French Top 14 winners, Clermont, and a Saracens team that would go on to win the Aviva Premiership title, both at the pool stage. The English champions, the Leicester Tigers, were dispatched in the quarter-final while Toulouse, the reigning European champions who went on to claim the French Top 14 crown the following month, were eclipsed in the semi-final.