German–Hungarian relations remained tenseas Boris attempted to take advantage of Conrad III's decision to lead a crusade to the Holy Land through Hungary. However Géza, who knew that "he could conquer more easily by gold than by force, poured out much money among the Germans and thus escaped an attack from them," according to the chronicler Odo of Deuil. The German crusaders marched across Hungary without major incident in June 1147.

The Illuminated Chronicle relates that some Hungarian noblemen promised Boris "if he could make his way into the kingdom, many would take him for their lord and, deserting the King, would cleave to him." Boris convinced two French noblemen to assist by hiding him among the French crusaders who followed the Germans towards the Holy Land. King Louis VII of France and his crusaders arrived in Hungary in August. Géza learnt that his opponent was with the French and demanded his extradition. Although Louis VII rejected this demand, he held Boris in custody and "took him out of Hungary," according to Odo of Deuil. Having left Hungary, Boris settled in the Byzantine Empire.