Numa Pompilius the second king of Rome, succeeding Romulus, began Rome's building projects with his royal palace the Regia and the complex of the Vestal virgins.
when the last of the seven kings of Rome, Tarquin the Proud, was deposed by Lucius Junius Brutus and a system based on annually elected magistrates and various representative assemblies was established.
The Roman empire expanded to become one of the largest empires in the ancient world, though still ruled from the city, with an estimated 50 to 90 million inhabitants (roughly 20% of the world's population In its many centuries of existence, the Roman state evolved from a monarchy to a Classical Republic and then to an increasingly autocratic empire.
Through conquest and assimilation, it eventually dominated the Mediterranean region, Western Europe, Asia Minor, North Africa, and parts of Northern and Eastern Europe.
Plagued by internal instability and attacked by various migrating peoples, the western part of the empire broke up into independent "barbarian" kingdoms in the 5th century.
After reaching Italy, Aeneas, who wanted to marry Lavinia, was forced to wage war with her former suitor, Turnus.
According to the poem, the Alban kings were descended from Aeneas, and thus Romulus, the founder of Rome, was his descendant.
By the end of the Republic (27 BC), Rome had conquered the lands around the Mediterranean and beyond: its domain extended from the Atlantic to Arabia and from the mouth of the Rhine to North Africa.
The Roman Empire emerged with the end of the Republic and the dictatorship of Augustus Caesar.