After passing a medical on Friday and agreeing personal terms Boro were able to apply for a work permit, which should be a formality, since he is far exceeds the required level of 75% in international over the last two years.
He will not be travelling to Austria tomorrow with the rest of the Boro squad but will be able to join them once the work permit comes through, possibly in time for Thursdays match with Udinese.
Steve McClaren expressed his delight at signing the 23-year-old Cameroon star by saying "I'm delighted to have finally signed a player that I first wanted last summer, especially as several other top clubs were interested in him. Geremi's a quality player who can play anywhere in midfield. He's a good athlete, strong and quick. He's got an excellent footballing pedigree, with great experience at both club and international level."
In his time at Real Madrid they have won the Champions League twice and last season he helped Cameroon lift the African Nations Cup.