Complex sentence: Pitti's cheif opponent at this time was Girolamo Machiavelli following his banishment, he travelled the neighbouribg principalities whipping opposition to the new Florentine government.
Split into simpler sentences: Pitti's cheif opponent at this time was Girolamo Machiavelli who was bannished. However, he travelled the neighbouribg principalities whipping up opposition to the new Florentine government.