Complex sentence: Amidst fears of a Huguenot coup, the Duke of Guise and his supporters acted and, in the early morning of August 24, killed Coligny in his lodgings with several of his men.
Split into simpler sentences: Amidst fears of a Huguenot coup, the Duke of Guise and his supporters acted. In the early morning of August 24, they killed Coligny in his lodgings with several of his men.