The Roman Empire unit test study guide provides an overview of the history and development of the Roman Empire from its origins as a kingdom in Rome to its eventual decline and fall. It covers the establishment of the Roman Republic and leaders like Julius Caesar who expanded Roman territory through military conquests. It also discusses the transition to an empire under Augustus and the influence and spread of Christianity. The guide outlines some of the key reasons for the fall of the Western Roman Empire and the continued existence of the Eastern Byzantine Empire centered in Constantinople until its conquest in 1453.