Middlesbrough have signed Sierra Leone international Alex Bangura from Dutch side SC Cambuur on a four-year deal.
The 24-year-old, who can play anywhere down the left side, has scored five goals in 113 games for the second-tier side, and has Eredivisie experience.
Bangura began his career with Rotterdam giants Feyenoord but failed to make a first-team appearance at the De Kuyp.
"He's a really exciting signing. He's a left-back and he's captained his team," boss Michael Carrick said.
"He's a good character with a great personality and he won't have any problem fitting into the group.