Portuguese champions Porto have signed central defender Chancel Mbemba from Premier League side Newcastle for a reported £7.14m fee.
The 23-year-old DR Congo international made 59 appearances, scoring once, after joining the Magpies for £8m from Belgian side Anderlecht in 2015.
"Everyone knows FC Porto are a great club," Mbemba told the club's website.
"It is a great happiness for me. I remember being in Africa and seeing Porto win the Champions League."