Ireland and Wales will kick off the 202 Six Nations Championship when they meet in Dublin on Saturday.
Intriguing individual contests will run through the game, but none more so than than the fly-half battle between Irish inspiration Johnny Sexton and new Wales captain Dan Biggar.
Here, the PA news agency looks at how two giants of northern hemisphere rugby match up.
Johnny Sexton – Leinster
Position: Fly-half
Age: 36
Caps: 101
Debut: vs Fiji, 2009
Height: 6′ 2″
Weight: 14st 2lbs
Points: 946 (15 tries)
Sexton has been the hard-drive of Ireland’s game for more than a decade, enjoying an outstanding career that has also produced British and Irish Lions recognition, in addition to driving Leinster towards European title successes.
He clocked up a century of Ireland caps during this season’s Autumn Nations Series, while he is also closing in on 1,000 points for his country.
At 36, he shows no sign of slowing down, and he will be a major figure behind Ireland’s quest for Six Nations silverware.
Dan Biggar – Northampton
Position: Fly-half
Age: 32
Caps: 95
Debut: vs Canada, 2008
Height: 6′ 2″
Weight: 14st 1lb
Points: 532 (7 tries)
If Biggar, who takes over Wales leadership duty from an injured Alun Wyn Jones, features in every Six Nations game this season, then he will end the tournament by winning his 100th Wales cap against Italy on March 19.
The Northampton number 10 has delivered numerous top-drawer displays for his country during a 13-year international career, combining match-winning moments with a fiercely-competitive edge.
Wales face a tough task in pursuit of a successful Six Nations title defence, but no-one will drive them harder than Biggar.