Complex sentence: Processions were announced in all the parishes of Paris for the following Sunday, and a reward of a hundred ecus was advertised for information leading to the arrest of the perpetrator or perpetrators, who were to be burned at the stake.
Split into simpler sentences: Processions were announced in all the parishes of Paris for the following Sunday. Also, a reward of a hundred ecus was advertised for information leading to the arrest of the perpetrator or perpetrators, who were to be burned at the stake.