Complex sentence: Favras took the unfortunate step of taking into his confidence certain officers by whom he was betrayed, With his wife, he was arrested on December 24,1789, and imprisoned in the Abbaye prison.
Split into simpler sentences: Favras took the unfortunate step of taking into his confidence certain officers by whom he was betrayed. As a consequence, he and his wife were arrested on December 24,1789, and imprisoned in the L'Abbaye Prison.