When Stephen was released in December of that year, Earl Geoffrey returned to his original allegiance. There has been much scholarly debate over the dating of the charters he received from King Stephen and Empress Matilda. Depending on the order and timing of those documents, either Geoffrey appears to have been playing off one against the other to get what he wanted or his support was courted by the rival claimants to the throne. The king arrested the earl in 1143 and, threatened with execution, Geoffrey surrendered his castles of Pleshey and Saffron Walden as well as custody of the Tower of London to Stephen. In reaction, Earl Geoffrey launched a rebellion .