Complex sentence: The Leuven gang lost and John III, Duke of Brabant gave the guild members permission to plant a Maypole each year on August 9; but this privilege would be lost if ever the people of Leuven managed to capture the tree before 5 PM.
Split into simpler sentences: The Leuven gang lost and John III, Duke of Brabant gave the guild members permission to plant a Maypole., each year on August 9. But this privilege would be lost should ever the people of Leuven manage to capture the tree before 5 pm.