Final answer:
Caesar had to suppress a revolt from Brutus and Cassius before going to Britain. He attempted to win over his former enemies by offering them positions in the Senate and government, but these efforts failed.
Step-by-step explanation:
Before going to Britain, Caesar had to suppress a revolt led by Brutus and Cassius. These former optimates viewed Caesar as a tyrant and led a conspiracy that resulted in his assassination. To stop the revolt, Caesar took measures such as inviting his former enemies to serve in the Senate and appointing them to positions in his government, but these efforts were unsuccessful in winning over the conspirators.