With the Super League Grand Final between Warrington Wolves and Wakefield Trinity taking place this weekend, attention turns to rugby league.
But several legendary players have made their mark in both codes, crossing from league to union or vice versa.
From international stars to club icons, we rank the greatest cross-code players in rugby history and look at the impact they made in both games.
5 Chris Ashton
After starting his career in rugby league with Wigan Warriors, Chris Ashton made the switch to union with Northampton Saints.
The transition could hardly have gone better, with Ashton scoring with his first touch for Saints and quickly establishing himself as one of the game's most dangerous finishers.
Across a 16-year career in the Premiership and Top 14, his blistering pace and superb support play became his trademark.
Finishing his career as the record try-scorer in both the Champions Cup and Premiership was a remarkable achievement and underlined just how prolific he was.
4 Lote Tuqiri
Starting out in rugby league, Lote Tuqiri eventually represented both Fiji and Australia before making the switch to union with the Wallabies.
His combination of power, pace and finishing ability made him a threat in either code.
The defining moment of his union career came in the 2003 Rugby World Cup final, when he scored Australia's only try against England.
Although league remained close to his heart and he eventually returned to South Sydney, his time with the Waratahs proved he could make a major impact in union too.
3 Israel Folau
Few careers have taken as many twists as Israel Folau's.
He first made his name in rugby league with Melbourne Storm before starring for Brisbane Broncos, Queensland and Australia.
A switch to Australian rules followed in 2011, with two seasons spent at Greater Western Sydney Giants before he returned to rugby through the Waratahs in 2013.
It did not take long for Folau to become one of the world's leading attacking players. He won 73 Australia caps and became Super Rugby's record try-scorer.
After leaving Australian rugby in 2019, he returned to league with Catalans Dragons before making another switch to union with Tonga. He now plays in Japan.
2 Jason Robinson
With more than 300 appearances for Wigan Warriors already behind him, Jason "Billy Whizz" Robinson had little left to prove in rugby league when he made the move to union.
His explosive pace and ability to break open games translated perfectly to the 15-man code.
At Sale Sharks, Robinson helped deliver the club's only Premiership title before becoming a key part of England's golden generation.
He went on to win the World Cup, earn five Lions caps and receive an OBE. Scoring in England's famous 2003 World Cup final victory over Australia provided the perfect highlight to an extraordinary career.
1 Sonny Bill Williams
Dominating in one code is impressive enough. Doing it across several sports is another matter entirely.
Sonny Bill Williams starred in the NRL before moving into union, where he became a World Cup winner with New Zealand. He also represented the All Blacks in sevens and enjoyed a successful professional boxing career, finishing with a 9-1 record.
His career was filled with headline-making moves, including the controversial switch from the Bulldogs to Toulon.
Very few players have matched Williams for versatility, athleticism and success across multiple sports, making his career one of the most remarkable in rugby history.
