Complex sentence: Mendoza retreated and the Spanish army then found itself in chaos mutinies took effect and as a result further operations were suspended for a number of years as the Dutch and English followed with a counter-offensive in the Spanish Netherlands.
Split into simpler sentences: Mendoza retreated and the Spanish army then found itself in chaos: mutinies took effect and as a result further operations were suspended for a number of years. As a result the Dutch and English followed with a counter-offensive in the Spanish Netherlands.