Which topic is often used as a theme for studying 20th century world history

Powers of states the first letter of the answer is r.

What is a key believes of john locke in establishment of government

Historians have recently discovered a historical journal published in the early twentieth century. the journal contains facts based on original sources about the downfall of the early byzantium empire. historians consider this long-lost journal to be a breakthrough in their understanding of the byzantium empire. based on this information, the journal is a source.