Respuesta :
he conquered many European kingdoms and fought off invaders is how did Charlemagne gather together many of the former Roman empire European territory's
Answer:
Through war.
Explanation:
Charlemange set the goal of uniting all of the german territories and beyond ant convert all of Western Europe to Christanity. In order to do so, he started many military campaigns to conquer other tribes like the Lombards in Italy, the Saxons in Germany, the Avars in Hungary and so on gathering together many of the former Roman Empire European territories.