Jobe Bellingham, younger brother of England star Jude, has joined Sunderland for an undisclosed fee.
Bellingham, 17, follows in the footsteps of his older sibling by leaving Birmingham but has decided to remain in the Championship with the Black Cats.
The talented midfielder enjoyed a breakout campaign in the Midlands in 2022-23, making 22 appearances in England's second tier.
He said: "I've been thinking about this for a long time and I can’t wait to get started.
"I spent many years at Birmingham and that really helped my development, but now felt like the right time to take the next step."
Bellingham will look to help the Black Cats win promotion to the Premier League after they reached the play-offs last term.
An attacking playmaker who has made three appearances for England Under-18s, he has signed a long-term contract at the Stadium of Light.
Bellingham will wear the No7 shirt and cannot wait to get play in front of the Sunderland faithful.
He added: "The Stadium of Light is the best atmosphere I’ve ever played in and the fans have already made me feel welcome online.
"I’m excited to get going and I’m focused on letting my football speak for itself."
Sunderland sporting director Kristjaan Speakman is confident Bellingham can become as big a star as Jude, who joined Real Madrid earlier this month.
He said: "Jobe's a player who is focused on being the best version of himself and for him to feel Sunderland can best support that progression is a massive endorsement of what we are doing.
"He has a great range of technical attributes and he will continue to develop physically, despite already showing he can shoulder the demands of Championship football.
"Like we do with all young players, we will give him time to settle and adapt to his new surroundings.
"But he can't wait to get out in front of our supporters at the Stadium of Light and I'm sure they will enjoy his journey with us."
