Complex sentence: During the 15th century, orders of chivalry, or dynastic orders of knighthood, became a mere courtly fashion that could be created "ad hoc", some of them purely honorific, consisting of nothing but the badge.
Split into simpler sentences: During the 15th century, orders of chivalry, or dynastic orders of knighthood, began to be created in a more courtly fashion that could be created "ad hoc". Ultimately, some of them were purely honorific, consisting of nothing but the badge.