I want to write a novel about Europe, so I need the names of past and modern countries in Europe (preferably a country name corresponds to the name of this country in the past)

Britain was called "United Kingdom of Great Britain and Northern Ireland" in ancient times;

Italy was called "Roman Empire" in ancient times;

Germany was called "Germanic Empire" in ancient times;

Russia was called "Tsarist Russia" in ancient times

Hero's name: Theseus ● Juedel

Heroine's name: Nataya ● Sileman.