Italy in Middle ages?

Question

The presence of (some place on the peninsula) caused Italy to not achieve national unity in the Middle Ages.

What place on the peninsula?

Answer 1

In 1815 at the close of the French Revolutionary and Napoleonic Wars the statesmen representing the great powers, in their efforts to restore stable governance to Europe after twenty-six years of turmoil, came to accept (under the persuasion of Talleyrand - the Foreign Minister of the recently restored French monarchy) that "legitimate sovereigns" should be restored, where possible, to their thrones.