Complex sentence: Later that year, William Fitz Osbern gave a fiery speech against the oppression of the poor at Paul's Cross and incited a riot which saw the cathedral invaded, halted only by an appeal for calm by Hubert Walter, Archbishop of Canterbury.
Split into simpler sentences: Later that year, William Fitz Osbern gave a fiery speech against the oppression of the poor at Paul's Cross and incited a riot in which the cathedral was invaded. The riot was only halted by an appeal for calm by Hubert Walter, Archbishop of Canterbury.