Rabbitohs second-rower Angus Crichton.

Round six in the Telstra Premiership just got a whole lot more interesting with the signing of promising South Sydney Rabbitohs back-rower Angus Crichton to the Sydney Roosters.

Thursday, April 12 at Allianz Stadium will host the two duelling clubs from Sydney's inner eastern and southern suburbs, where not much love has transpired over the past 110 years.

And now Crichton is committing the ultimate sin – signing with the Bondi Junction club for three years from 2019. He is leaving the Redfern burrow and fans will be seething.

The foundation clubs despise each other – so much so that when rabid Rabbitohs supporter Russell Crowe took over ownership in 2006, he compiled the "Book of Feuds" to teach his players why Souths will never forget past wrongs.

A whole chapter is devoted to the Roosters and it starts like this: "There is no greater rivalry in the NRL than that between the Rabbitohs and the Roosters. As the only remaining foundation clubs, they have played more matches between them than any other two clubs."

Despite the ups and downs in results between these two clubs and the geographical location of living right next door to each other, comes the real root of the long-standing feud – pinching players.

In 1971 international winger Michael Cleary became the first of a long line of players to move from Redfern to Bondi Junction. He was soon followed by the great Ron Coote in 1972 and Test hooker Elwyn Walters in 1974, the last two being instrumental in the Roosters' back-to-back 1974-75 titles.

But more salt was rubbed into an open wound when after the Rabbitohs were dumped from the first-grade competition in October 1999 in the Super League aftermath, one of South Sydney's top young talents, Craig Wing, sat down before the media microphones in a Roosters jersey for the upcoming 2000 season.

Playing in the halves alongside Brad Fittler, he won the 2002 premiership with the Roosters – the year Souths returned to the NRL, finishing 14th. Three wooden spoon seasons followed over the next four years before Souths made the finals in 2007 for the first time since 1989. Wing announced in June 2007 he would be returning to Souths on a four-year deal.

Crichton is off to the Tricolours on a three-year deal from 2019. With the Roosters loading up cattle onto the wagon of the calibre of James Tedesco and Cooper Cronk, another premiership might not be far away.

The 21-year-old missed out on South Sydney's breakthrough 2014 premiership – 43 years after their last one – as he didn't make his NRL debut until round 19 of 2016.

The strong-running forward is viewed as future representative material. Incoming NSW coach Brad Fittler has already mentioned him in a list of the "next generation" players he would be keeping his eye on in 2018.

So maybe Crichton will gain his first senior rep jumper while still in Souths colours.

But undeniably he is the biggest player to switch to the dreaded down-the-road Roosters since Wing. Then again 2014 premiership-winning five-eighth Luke Keary jumped the fence in 2017 after a breakdown in his relationship with Crowe.

Rabbitohs second-rower Angus Crichton.
Rabbitohs second-rower Angus Crichton. ©NRL Photos

Crichton's worth is also measured by the fact the Cronulla Sharks had a big bite at him.

Sharks coach Shane Flanagan wanted him in his pack as he prepares for the impending retirements of Paul Gallen and Luke Lewis.

Crichton's management confirmed Rugby Australia came calling earlier in 2017. But there had been no subsequent talks in the dying embers of this year when it became apparent a few NRL clubs were after the youngster's signature.

Many Rabbitohs fans will be asking why? Perhaps because Crichton's age and his relative NRL inexperience means he hasn't had enough time to absorb the hate between the two clubs – perhaps because the players get along fine.

But when Souths dropped Nathan Merritt from first grade in late 2014, after he announced his retirement at the end of the season, one of the winger's relatives started turning up to Redfern Oval training sessions in a Roosters jersey.

In 2019 when Crichton runs out clad in a Roosters jersey to oppose his Souths teammates for the first time, he will truly understand why his move has created such a storm.