Lucius Tarquinius Priscus in the context of "Demaratus of Corinth"

The king of Rome (Latin: Rex Romae) was the ruler of the Roman Kingdom, a legendary period of Roman history that functioned as an elective monarchy. According to legend, the first king of Rome was Romulus, who founded the city in 753 BC upon the Palatine Hill. Seven legendary kings are said to have ruled Rome until 509 BC, when the last king was overthrown. These kings ruled for an average of 35 years.

The kings after Romulus were not known to be dynasts and no reference is made to the hereditary principle until after the fifth king Tarquinius Priscus. Consequently, some have assumed that the Tarquins' attempt to institute a hereditary monarchy over this conjectured earlier elective monarchy resulted in the formation of the Republic.

Lucius Tarquinius Superbus (died 495 BC) was the legendary seventh and final king of Rome, reigning 25 years until the popular uprising that led to the establishment of the Roman Republic. He is commonly known as Tarquin the Proud, from his cognomen Superbus (Latin for "proud, arrogant, lofty").

Ancient accounts of the regal period mingle history and legend. Tarquin was said to have been either the son or grandson of Lucius Tarquinius Priscus, the fifth king of Rome, and to have gained the throne through the murders of both his wife and his elder brother, followed by the assassination of his predecessor, Servius Tullius. His reign has been described as a tyranny that justified the abolition of the monarchy.

Servius Tullius was the legendary sixth king of Rome, and the second of its Etruscan dynasty. He reigned from 578 to 535 BC. Roman and Greek sources describe his servile origins and later marriage to a daughter of Lucius Tarquinius Priscus, Rome's first Etruscan king, who was assassinated in 579 BC. The constitutional basis for his accession is unclear; he is variously described as the first Roman king to accede without election by the Senate, having gained the throne by popular and royal support; and as the first to be elected by the Senate alone, with support of the reigning queen but without recourse to a popular vote.

Several traditions describe Servius's father as divine. Livy depicts Servius's mother as a captured Latin princess enslaved by the Romans; her child is chosen as Rome's future king after a ring of fire is seen around his head. The Emperor Claudius discounted such origins and described him as an originally Etruscan mercenary, named Mastarna, who fought for Caelius Vibenna.

The gens Tarquinia was a plebeian family at ancient Rome, usually associated with Lucius Tarquinius Priscus and Lucius Tarquinius Superbus, the fifth and seventh Kings of Rome. Most of the Tarquinii who appear in history are connected in some way with this dynasty, but a few appear during the later Republic, and others from inscriptions, some dating as late as the fourth century AD.

Lucumo, in Etruscan lauchme or lauchume, was a title of Etruscan rulers, equivalent to the Latin rex, or "king". In Roman sources, it is frequently mistaken for a personal name, particularly in the case of Lucius Tarquinius Priscus, the fifth King of Rome, a native of Etruria who is said to have adopted a Roman name in place of his original name, Lucumo. Heurgon compares this to the Etruscan use of the Roman magister, "magistrate", as a personal name in the case of Servius Tullius, the sixth Roman king, known in Etruscan as the hero "Macstarna".

Although much of what is known of the Etruscans from Roman literature refers to their kings, the various Etruscan city-states seem to have abolished their monarchies around the same period as the establishment of the Roman Republic. The lucumones were replaced by magistrates bearing the title of zilath, evidently the Etruscan equivalent of magister. In later times, Lauchme survived as an Etruscan surname.