Answer:
It was cut off from the prosperous trade routes in the Eastern Roman Empire
Explanation:
Constantine had weakened the West during his rule, other than favouring the East in development of infrastructure, but in economic governance too. He raised taxes in the West to bring them up to the level of those in the East to seem fair. This did not take into account the economic disparities between the two halves of the Empire, and the extra taxes on the West served to further cripple their economy, which had dwindled due to the constant pressures of war and low trade.
