Popular sovereignty, or the sovereignty of the peoples' rule, is part of the seven principles, that the authority of a state and its government is created and sustained by the consent of its people, through their elected representatives (Rule by the People), who are the source of all political power.
Victor Emmanuel the second was the first king of Italy.
The Reign of Terror came to an end, because the man who had started the Reign of Terror (Robespierre) was executed. The Reign of Terror also came to an end, because nuns had been executed because they did not want to give up their monastic vows and they were very calm during the execution, so this shifted the mood in Paris, probably making the general population realize that the mass executions were futile.
An absolute monarchy is a form of monarchy in which the monarch (king or queen) holds absolute power over their kingdom. They have no limits over how they rule, meaning that they are not restricted by any written laws, customs or legislature.