Possible Clues:

• Bloody period of the French Revolution
• It was frightful, as a rule
• Frequently slip after shower, we hear, in dark period
• Period for Marie Antoinette's doom
• What Robespierre started, as a rule, frequently a mistake
• What king does frequently a mistake - the French Revolutionary experience
• Frequently slip after wet weather, say, having awful time in France
• Bloody period of French Revolution
• That sounds like a frightful downpour
• Period of Jacobin rule in France