Considering its longevity and organization, the Roman Empire contributed little to the development of diplomacy. This may be explained by their will to impose their policies on others instead of negotiating. 

It is widely accepted that the contribution of Romans to diplomacy is much more related to the international law and is represented in the theory, not the practice, of diplomacy.

In the early years of the Roman Republic, procedures similar to those developed in Greece were used. People were expressing their will through popular assemblies, and therefore were arbiters of diplomatic issues such as war, peace and treaties. Envoys from foreign powers never came before the assemblies of the people. However, as Rome came to power, the Senate took over the authority and gained a disproportionate influence, along with the right of choosing and instructing envoys and of receiving incoming embassies. After the empire was established, diplomacy turned to be part of regular government policy which was in the hands of the emperor, despite the Senate remained.