Confirmation of former Barcelona goalkeeper Victor Valdes' arrival at Middlesbrough, on a two-year contract, makes him just the latest decorated name to unexpectedly join the club.
Here's a look at their strongest and most illustrious XI from the Premier League era.
The goalkeeper of perhaps the world's greatest ever football team - Pep Guardiola's Barcelona of 2008-2012 - Valdes won three Champions League trophies before becoming David de Gea's understudy at Manchester United.
Played at right-back for three European giants - Ajax, AC Milan and Barcelona - as well as Holland when they had one of the world's strongest squads. Reiziger spent a year at Middlesbrough from 2005.
The central defender won 57 England caps in a highly-competitive era when Tony Adams, Sol Campbell, Rio Ferdinand and Martin Keown were also at their collective peak. In 2006 he succeeded Steve McClaren as manager.
First arrived on loan from Real Madrid, who had spent £13.4million on him, before joining the club on a permanent basis in 2007. His second spell started in 2012 and ended earlier this summer.
The Germany international impressed in his one season at the club, from 1999 having joined from AC Milan, and scored seven times before controversially joining Liverpool for £5.5million.
Arrived on loan from Lazio in 2003, having cost the Italians £28.9million from Valencia two years earlier as a replacement for Juan Sebastian Veron. The two-time Champions League finalist spent five years at the club, in which they won the 2004 League Cup.
Spent two years at Middlesbrough after joining from Rangers and helped them secure promotion to the Premier League in 1998. Two years later he joined Everton on a free transfer, with his career obviously in decline despite his occasional flashes of brilliance.
The France international cost £2.1million from Real Madrid in 2000. He had won a World Cup, and the Champions League twice, but Middlesbrough struggled during his one season there before he left for Olympiakos.
Perhaps Middlesbrough's greatest ever player, Juninho was so impressive throughout his first season, from 1996, that Atletico Madrid paid £12million for him. He returned on loan in 1999 before signing permanently in a third spell from 2002, in which they won the 2004 League Cup, their first ever trophy.
The Italian's 33 goals in the 1996/97 season inspired them to the FA and League Cup finals, more than justifying his £7million transfer fee, but they were also relegated from the Premier League.
The classy Croatian cost only £2.5million from Lazio in 2000. He was also paid what was then an eye-watering wage of £64,000 per week, but justified it with the entertaining displays that brought 22 goals until injuries forced his retirement in February 2003.