The Rugby League World Cup final takes place at Old Trafford this weekend with Sonny-Bill Williams bidding to add a 13-man winner’s medal to his 2011 union victory.
Williams is one of hordes of talented rugby players to hit the heights in both codes of the oval ball game.
Everyone on this list has played in and won pivotal matches on both sides of the divide, amassing a truckload of points, caps and honours for club, region, province and country.
There are plenty of those who have not made the cut, perhaps excelling in one code, but not both, to the degree our final 10 managed.
Let’s start with the honourable mentions.
Scotland’s Alan Tait found union fame on the 1997 Lions tour after a league career with Widnes and Leeds, as did Allan Bateman.
Martin Offiah converted to league early in his union career and became one of the 13-man game’s greatest wings.
Lesley Vainikolo was a devastating member of the powerful Bradford Bulls rugby league side and became a cult hero when he switched codes to join Gloucester. But his England career was short-lived in union.
The Paul brothers both left league for union, with Henry fairing better than brother Robbie, but never truly winning over the hearts and minds of Twickenham Man in a six-cap England career.
Down Under, Wendell Sailor and Mat Rogers both played in the 2003 union World Cup final after making the switch.
Rogers will, perhaps, be best remembered by England fans for Josh Lewsey’s jackhammer tackle on him in 2003.
Current England coach Andy Farrell had a glittering league career but was perhaps past his best by the time he joined Saracens.
Bentley won his place in the hearts of every British and Irish Lions fan with his starring role in the 1997 film about the tour.
Bentley was one of a number of ex-rugby league players picked by Sir Ian McGeechan for the tour to bring a sense of professionalism that was still novel to the rest of the squad finding their way in the brave new world.
Bentley, who had left union for league in the late 1980s after two England caps, scored some scintillating tries in the tour matches for the Lions and started the second Test that sealed series victory.
Bentley, who played for England in the 1995 league World Cup, played union twice more for England after the tour but went back to league with Huddersfield as his playing career wound down.
Gibbs was just 22 when he earned two Lions Test caps on the 1993 tour of New Zealand, unseating then-England captain Will Carling.
A year later he signed for St Helens in the 13-man game, a move that caused a huge upset at his former club Swansea.
He played for Wales in the 1995 World Cup.
Gibbs won the Super League and Challenge Cup with the Saints in 1996, but, when union turned pro, Gibbs came back.
The bullocking centre was another cornerstone of the winning 1997 Lions side, famously landing South African enforcer Os du Randt on his backside in the first test.
In 1999, he scored the last ever try in the Five Nations Championship to seal a famous win over England at Wembley.
Botica was understudy to the great Grant Fox in the 1987 World Cup-winning New Zealand side.
He earned 27 All Black caps before converting to rugby league where he became a star for Wigan, becoming the fastest man to reach 1000 points for the club.
He won seven caps for the Kiwis in league but switched back to union after the dawn of professionalism.
After spells with Llanelli and in France, Botica even turned out for Croatia in a World Cup qualifier in the late 1990s.
Davies was one of the code-crossing trailblazers in the amateur days of rugby union.
After emerging as a talented young star for Wales and skippering the side, he opted for the more professional surroundings of league and joined Widnes.
He spent three seasons there before joining Warrington and became a leading light for Great Britain, scoring in a victory over Australia in 1994. He was also named Man of Steel that year.
In the mid-to-late '90s, union was lurching towards professionalism, and Davies returned, signing for Cardiff.
He won five more union caps, his last in 1997, and has since become a regular pundit and co-commentator for the BBC on both codes of rugby.
The man known as "Inga the Winger" became one of the key components of Newcastle’s title-winning season in 1998.
It was one highlight in a career that had many. He made his All Blacks debut in 1991 but joined Wigan in rugby league in 1993, where he excelled.
Tuigamala enjoyed Challenge Cup victories in 1994 and 1995 and played for the Samoan league side in the 1995 World Cup.
The newly professional union lured him back, and the deep pockets of Sir John Hall delivered the powerful winger to the North East.
Promotion to the Premiership was followed by the league title in ’98 and the cup in 2001.
His international career continued for Samoa, totaling 23 tests, including the 1999 union World Cup.
Thorn made his name for the Brisbane Broncos in league before his first appearance for the Kangaroos in 1997.
The abrasive second rower returned to the land of his birth in 2001 and switched codes to play for the Crusaders in Super Rugby.
His All Blacks debut came in 2003, and he played in the World Cup of that year before hopping back across the Tasman to pick up his league career again in 2005.
After three more seasons with the Broncos, union came calling again in 2007, and Thorn starred once more for the Crusaders and made it back in to the national setup.
He picked up a World Cup winner’s medal in 2011 and joined Leinster later that season, where he helped them to the 2012 Heineken Cup.
After making his debut for the Welsh national rugby union side in 1993, Quinnell switched codes, signing for Wigan.
There, he won the league and the Regal Trophy amid a galaxy of star players. He also played for Wales in the 1995 league World Cup.
Quinnell returned to union in 1996 as one of a host of top names who signed for Richmond in the club’s doomed attempt to establish themselves as a top flight fixture.
In 1998, Quinnell went back to where it all started at Llanelli, having toured with the Lions in 1997.
He went on to amass 52 Welsh caps, establishing himself as a true Welsh great and one of the world’s best No. 8's.
Quinnell played in all three Tests on the 2001 Lions tour, scoring in the opener. He retired in 2005 and has forged a career as one of TV’s foremost rugby pundits with Sky Sports.
The big Fijian-born wing made his name for the Brisbane Broncos, a powerhouse of Australian rugby league.
He scored in their NRL Grand Final win in 2000 and skippered the Fijian national side in the 2000 Rugby League World Cup.
A year later, he switched allegiances to the Kangaroos and scored for the Australian national side on debut against New Zealand.
Tuqiri had by now become the best wing in the sport and was attracting attention from the 15-man game.
In 2002, the Australian Rugby Union made him an offer he couldn’t refuse, and he joined the New South Wales Waratahs.
He made his debut for the Wallabies in 2003 against Ireland and was a key component of their World Cup squad alongside fellow converts Mat Rogers and Wendell Sailor.
Tuqiri scored in the final, out-jumping fellow code-crosser Jason Robinson for his try.
An acrimonious split with the ARU in 2009 saw Tuqiri head north, where he joined Leicester Tigers for a brief stint before heading back to the 13-man game.
In 2010, he became the first code-crosser to play test rugby league for Australia a second time after returning from rugby union.
He had one more dalliance with union when he signed a short-term deal with Irish province Leinster in 2012.
Williams has not only proved himself one of the best code-crossers in the business, he also has a decent right hook, with six professional heavyweight wins from six bouts.
The current heavyweight champ of New Zealand began his career in league with the Canterbury Bulldogs but left them in 2008 to join the star-studded Toulon in rugby union.
He made his All Blacks debut in 2010, and his outstanding ability to offload the ball out of the tackle made him a potent weapon in the Blacks’ World Cup side of 2011.
With his winner’s medal round his neck, Williams soon returned to rugby league with the Sydney-based Roosters and is a part of the current Kiwis side set to face Australia in the 13-man World Cup final this weekend.
Billy Whizz was a Wigan legend in rugby league when he was tempted across the divide.
His first foray came at Bath in 1996 for a 13-game stint, but he made the switch permanently in 2000 with Sale Sharks after 300 appearances for the dominant Wigan outfit and 12 caps for Great Britain.
The innovative mindset of England coach Clive Woodward meant it wasn’t long before Robinson found himself in the England squad.
He hadn’t even started a game at international level when he was picked for the Lions squad in 2001.
He lit up Brisbane with a startling first try, zipping past experienced Wallaby Chris Latham like he wasn’t even there.
Robinson hit even greater heights with England’s only try of the 2003 World Cup final, securing his legacy as one of the greatest players of all time in either code.
He retired from the international scene in 2005 only to return in 2007, reaching another World Cup final where England lost to South Africa.