Australian Test centre Israel Folau said the chance to return home to his family in Brisbane was the key factor in his decision to leave Melbourne Storm to join the Broncos from next year.
Folau had been in discussions with the Broncos for some time and on Sunday the 18-year-old alerted both clubs and his teammates of the move.
"It was a very tough decision, the hardest of my life, to leave the Melbourne Storm and sign for the Broncos," Folau said in a statement.
"The club has been like a family to me in Melbourne and without their support I wouldn't have been able to achieve what I did.
"But the opportunity to return home and be closer to my family was too hard to resist. My family is the most important thing in my life and they are the reason I have made this choice."
Storm chief executive Brian Waldron was disappointed with the decision but said he understood why Folau, a devoted Mormon, decided to leave.
"Israel's family and church are very important to him and he can be closer to both at home in Brisbane," Waldron said.
"The impact Israel has made in Melbourne in his short time with the club has been phenomenal, and for that he will always be remembered with great affection.
"For a 17-18-year-old to break our season try-scoring record, win a premiership and become the youngest Australian Test player in history goes to show not only how talented he is, but what terrific structures we have in place here in Melbourne for anyone who plays for the club."
The Broncos also confirmed the signing on their website and chief executive Bruno Cullen will hold a press conference at the Red Hill training venue at 10am on Monday.