The Roman Empire existed on Earth from 31 BCE to 476 CE and was one of the most powerful of the planet's early civilizations.
The territory of the Romans extended primarily through the region of the Mediterranean, encompassing parts of Africa, Europe, and Asia Minor. The Empire was governed by a Senate and, for most of its history, an Emperor who was sometimes referred to as "Caesar" after Julius Caesar.
Though the Empire brought many technological and societal advances into being on Earth it had a dark side that included brutal military campaigns and gladiatorial combat for public entertainment. Religious dissidents were also brutally persecuted.
The planet 892-IV, which evolved according to Hodgkin's Law of Parallel Planetary Development, had a similar government to the Roman Empire, though that government persisted for much longer. (TOS: "Bread and Circuses")
In 2366, while Jean-Luc Picard contemplated the impending battle with the Borg, he wondered if while the Emperor Flavius Honorius watched the Visigoths coming over the seventh hill truly realized that the Roman Empire was about to fall. (TNG: "The Best of Both Worlds")
Background
The screenwriters based many of the elements of the government of the Romulan Star Empire such as Praetor, Proconsul, and the Romulan Senate on Roman precedents. The twin capitals of the Empire Romulus and Remus are also named after the traditional founders of Rome. Many other similar aspects such as officers holding the rank of Centurion, and the Imperial Eagle also enforce this.