A controversy had occurred in the Northumbrian church over the date of Easter. The king Oswiu of Northumbria and his son Eahlfrith each backed a different church position. Why Agilbert came to Northumbria at this time or who sent him is not recorded. But kings Osiwu and Cenwalh were friends. They both supported the Roman position that Easter should be celebrated the same throughout the Christian world. A synod was called at Whitby to settle the issue. Bishop Agilbert was the senior there who supported the Roman position. As he did not speak the language well, he asked Wilfrid to speak for him. Their argument was why did only the remote parts of Britain celebrate Easter differently than the remainder of the Christian world? Osiwu made a decision to celebrate Easter with the rest of the Christian churches.