The next chapter in an emerging European rivalry will unfold this weekend.

Leinster and Northampton Saints have played out some of the most dramatic clashes in the history of rugby at Europe’s top table.

And here we take a look back at some of those classic clashes.

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Of course we begin in Cardiff with the 2011 final.

The Johnny Sexton half-time speech that has gone down in history as the boys in blue came roaring back to claim an incredible 33-22 victory.

Saints came flying out of the blocks as Phil Dowson, Ben Foden and Dylan Hartley all crossed before half-time.

But Leinster, chasing a second title in three years, were not to be denied.

Sexton issued the rallying call at the break as they trailed 22-6, and having talked the talk he went out and walked the walk in the second half.

The fly-half crossed for a try double, kicked two more penalties and Nathan Hines dotted down in the final quarter to seal an incredible turnaround.

FRANKLIN FAILURE

Drawn together in the ²⁰¹³⁄₁₄ season, Saints showed their mettle in a campaign that ended with their first ever Premiership title.

But before the glory, there was the gutting.

At Franklin’s Gardens, no less, they crashed into a runaway train in Leinster with Brian O’Driscoll in imperious form.

Leinster's Brian O'Driscoll goes off injured

The game is best remembered for BOD’s incredible through-the-legs pass that released Luke Fitzgerald to score.

But the winger also got a hat-trick that day, including a double inside the first eight minutes as Leinster effectively won the game before Saints had fired shot.

Eoin Reddan and Jamie Heaslip also crossed in the 40-7 win as O’Driscoll got the try his performance deserved in the second half.

SAINTS MARCH INTO DUBLIN

But a week later at the Aviva Stadium, Saints were simply sublime.

With an injury-hit back line that had George North parachuted into the centres and Ken Pisi at full-back, they arrived in Dublin expecting a beatdown.

But an amazing defensive performance saw them hold Leinster tryless, while North went over inside five minutes to give them a lead they would never relinquish.

The boot of Stephen Myler and a Kahn Fotuali’i drop goal kept Leinster at bay but with time winding down they were defending for their lives on their own line after a searing Jamie Heaslip break.

But a Jamie Elliott interception and length-of-the-field sprint sealed an amazing turnaround win and denied Leinster even a losing bonus point at the Aviva Stadium.

CHRISTMAS CRUNCH

The rivalry continued with Christmas fixtures in the ²⁰¹⁶⁄₁₇ season, but this time Leinster were far too strong.

They ran riot at Franklin’s Gardens first with a 37-10 win but the real story was undoubtedly the red card shown to Dylan Hartley.

In a Lions year, Hartley did himself no favours with a swinging arm tackle on Sean O’Brien that saw him given his marching orders.

Garry Ringrose had gone over in the first minute of the game but the damage actually came in the second half when Leinster had numerical supremacy.

O’Brien, Rory O’Loughlin, Jamison Gibson-Park and Isa Nacewa all went over as Saints were embarrassed on home soil.

MAGNIFICENT EIGHT

But that was nothing compared to the Aviva annihilation that awaited the fallen Saints a week later.

60-13 was the final scoreline and in truth it could have been more.

Leinster ran in eight tries in all, and had secured a bonus-point win even before half time.

Adam Byrne bagged a first-half double while Luke McGrath and O’Brien also went over to leave the Saints reeling.

And after the break, Tadhg Furlong got in on the act, as did his front-row colleague Sean Cronin before O’Loughlin and Nacewa rounded out the scoring on a lovely Leinster night.