Sunderland have signed Birmingham midfielder Jobe Bellingham for an undisclosed fee, on the same day his older brother Jude completed a move to Real Madrid from Borussia Dortmund.
Like England international Jude, Jobe, 17, came through the Blues' academy and made his senior debut aged 16.
He made 23 appearances in all competitions last season.
Sunderland have said Bellingham will complete the transfer when he returns from England Under-18 duty.
"I'm delighted to sign for Sunderland and I can't wait to get started," he told the club website.
"The opportunity for young players to move here and progress is clear, so I believe this is the perfect club for me to continue my development.