German Bundesliga giants Borussia Dortmund have re-signed defender Mats Hummels from rivals Bayern Munich after three years with the Bavarian giants.
His transfer was announced on Wednesday afternoon by Borussia Dortmund.
Mats Hummels had earlier joined Bayern Munich on a free transfer in 2013 after his Borussia Dortmund contract ran out.
The 30-year-old had spent eight years at the Signa Iduna Park before his controversial exit there years ago.
Mats Hummels won two German Bundesliga titles, one German Cup and two German Super Cup titles during his first spell as a Borussia Dortmund player.
In addition, the recently retired German international was part of the Borussia Dortmund team that reached the 2013 Champions League final under the guidance of current Liverpool boss Jurgen Klopp.
Hummels and Dortmund were beaten 2-1 by Bundesliga rivals Bayern Munich in that all-German Champions League final at the Wembley Stadium.
He was linked with a move to Premier League giants Manchester United last summer but the German centre back opted to stay with Bayern Munich whom he helped win a seventh successive league title last season.
Bayern sealed another Bundesliga title ahead of Borussia Dortmund on the final day of the season.
Borussia Dortmund tried to sign both Jerome Boateng (Bayern Munich) and Laurent Koscielny (Arsenal) before they agreed on a deal for Hummels.