 After the conquest of Gaul there was no more room for expansion and there was the task defence from attacks of the borders in Europe in the face of a reduction in size of the Roman army.In an economic context there was the question of control over the rich gold mine at Las Medullas (the richest in the empire) in Asturia and the abundant iron ores of Cantabria.Towards the end of the Roman Civil Wars there was a shortage of gold and silver.