Arsenal have completed the signing of Belgium Under-21 international Albert Sambi Lokonga from Anderlecht.
The 21-year-old midfielder made his debut for Anderlecht in 2017 and has gone on to make 78 appearances for the Belgian side.
He is Arsenal's second signing of the summer following the arrival of fellow 21-year-old defender Nuno Tavares from Benfica.
"Albert is a very intelligent player who has shown great maturity in his performances during his development," Gunners boss Mikel Arteta told the club website.
"He has been coached well by Vincent Kompany and his team at Anderlecht. I know Vincent very well and he talks so highly about Albert and the positive impact he had to Anderlecht in recent seasons.
"We're confident Albert's ready for the next stage in his development and we're looking forward to welcoming a new member to our squad with his quality and presence."
Lokonga received a call-up to Roberto Martinez's senior Belgium squad in March but was an unused substitute. He has been capped seven times at U21 level for the country.
Arsenal finished eighth in the Premier League last season and will begin their 2021-22 campaign at newly promoted Brentford on 13 August.