This congress had led to germany and italy being divided

The name of the congress that led to Germany and Italy being divided, is called the Congress of Vienna.

Explanation:

The Congress of Vienna (constituted after the downfall of Napoleon Bonaparte who had taken territories away from some States, and added them to others) led to Germany and Italy being divided. The congress-which aimed at creating borders for States, balancing the powers of States, and preventing future wars in Europe-divided Germany and Italy, which, prior to the congress, had a special relationship as a result of their States (territories) lying side by side to each other in the Holy Roman Empire of the time, and fighting together against the Austrian Empire.