The Western parts of the empire, with the exception of Africa and Italy, were all passed down to Constantine II, the eldest son of Constantine I.

Not content with just this, he intimidated his brother Constans and attempted to take these things from him.

When Constantine the elder lost patience and shut off contact, Constans retaliated by sending his troops into Northern Italy.
But Constans was ready to meet him because he had foreseen these occurrences.

As a result of being caught off guard by this counterattack, Constantine was killed during the battle and his property was taken by Constans.