Complex sentence: On the morning of the 17th of March all of the detached outposts surrounding the castle had been taken by surprise and were captured by the Jacobites and the government soldiers of the outposts were made prisoners.
Split into simpler sentences: On the morning of the 17th of March all of the detached outposts surrounding the castle had been taken by surprise and were captured by the Jacobites. The government soldiers of the outposts were made prisoners.