[1] 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.

Livy depicts Servius' 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.

He is traditionally credited with the institution of the Compitalia festivals, the building of temples to Fortuna and Diana and, less plausibly, the invention of Rome's first true coinage.

On the one hand, Romulus was held to have brought Rome into being more-or-less at a stroke, so complete and purely Roman in its essentials that any acceptable change or reform thereafter must be clothed as restoration.

On the other, Romans of the Republic and Empire saw each king as contributing in some distinctive and novel way to the city's fabric and territories, or its social, military, religious, legal or political institutions.

[8] The oldest surviving source for the overall political developments of the Roman kingdom and Republic is Cicero's De republica ("On the State"), written in 44 BC.

[9] The main literary sources for Servius' life and achievements are the Roman historian Livy (59 BC – AD 17), whose Ab urbe condita was generally accepted by the Romans as the standard, most authoritative account; Livy's near contemporary Dionysius of Halicarnassus, and Plutarch (c. 46 – 120 AD); their own sources included works by Quintus Fabius Pictor, Diocles of Peparethus, Quintus Ennius and Cato the Elder.

[10] Livy's sources probably included at least some official state records, he excluded what seemed implausible or contradictory traditions, and arranged his material within an overarching chronology.

Rome's military and territorial expansion and consequent changes in its population would have made franchise regulation and reform an ongoing necessity, and their wholesale attribution to Servius "cannot be taken at face value".

[24] Until the Servian reforms, the passing of laws and judgment was the prerogative of the comitia curiata (curiate assembly), made up from thirty curiae; Roman sources describe ten curiae for each of three aristocratic tribes or clans, each supposedly based on one of Rome's central hills, and claiming patrician status by virtue of their descent from Rome's founding families.

The senate advised the king, devised laws in his name, and was held to represent the entire populus Romanus (Roman people); but it could only debate and discuss.

[25] Rome's far more populous citizen-commoners could participate in this assembly in limited fashion, and perhaps offer their opinions on decisions but only the comitia curiata could vote.

[30] A citizen's wealth and class would, therefore, have defined their position in the civil hierarchies, and up to a point, within the military; but despite its apparent military character, and its possible origins as the mustering of the citizenry–at–arms, the system would have primarily served to determine the voting qualifications and wealth of individual citizens for taxation purposes, and the weight of their vote – wars were occasional but taxation was a constant necessity[31] – and the comitia centuriata met whenever required to do so, in peace or war.

The wealthiest class of iuniores (aged 17–45) were armed as hoplites, heavy infantry with helmet, greaves, breastplate, shields (clipeus), and spears (hastae).

[citation needed] Some Roman historians believed Servius Tullius responsible for Rome's earliest true, minted coinage, replacing an earlier and less convenient currency of raw bullion.

Rather, wealthy landowners would make an "advance loan" of seed, foodstuffs or other essentials to tenants, clients and smallholders, in return for a promise of labour services or a substantial share of the crop.

[41] Servius is credited with the construction of Diana's temple on the Aventine Hill, to mark the foundation of the so-called Latin League;[42] His servile birth-mythos, his populist leanings and his reorganisation of the vici appear to justify the Roman belief that he founded or reformed the Compitalia festivals (held to celebrate the Lares that watched over each local community), or allowed for the first time their attendance and service by non-citizens and slaves.

[43] His personal reputation and achievements may have led to his historical association with temples and shrines to Fortuna; some sources suggest that the two were connected during Servius' lifetime, via some form of "sacred marriage".

For Livy, Tarquinius' impious refusal to permit his father-in-law's burial earned him the sobriquet Superbus (“arrogant” or “proud”),[46] and Servius' death is a "tragic crime" (tragicum scelus), a dark episode in Rome's history and just cause for the abolition of the monarchy.

Servius thus becomes the last of Rome's benevolent kings; the place of this outrage – which Livy seems to suggest as a crossroads – is known thereafter as Vicus Sceleratus (street of shame, infamy or crime).

[50] Livy and Dionysius ignore or reject the tales of Servius' supernatural virgin birth; though his parents came from a conquered people, both are of noble stock.

[51] The details of Servius' servile birth, miraculous conception and links with divine Fortuna were doubtless embellished after his own time, but the core may have been propagated during his reign.

The victors include Aule and Caile Vipinas – known to the Romans as the Vibenna brothers – and their ally Macstrna [Macstarna], who seems instrumental in winning the day.

Claudius was certain that Macstarna was simply another name for Servius Tullius, who started his career as an Etruscan ally of the Vibenna brothers and helped them settle Rome's Caelian Hill.

Claudius' "Etruscan Servius" seems less a monarch than a freelance Roman magister, an "archaic condottiere" who placed himself and his own band of armed clients at Vibenna's service,[57] and may later have seized, rather than settled Rome's Caelian Hill.

If the Etruscan Macstarna was identical with the Roman Servius, the latter may have been less monarch than some kind of proto-Republican magistrate given permanent office, perhaps a magister populi, a war-leader, or in Republican parlance, a dictator.

[60] Servius' connections to the Lar and his reform of the vici connect him directly to the founding of Compitalia, instituted to publicly and piously honour his divine parentage – assuming the Lar as his father – to extend his domestic rites into the broader community, to mark his maternal identification with the lower ranks of Roman society and to assert his regal sponsorship and guardianship of their rights.

In Servius, Augustus found ready association with a popular benefactor and refounder of Rome, whose reluctance to adopt kingship distanced him from its taints.

[61] He did not, however, trace his lineage and his re-founding to Servius – who even with part-divine ancestry still had servile connections – but with Romulus, patrician founding hero, ancestor of the divine Julius Caesar, descendant of Venus and Mars.

Plutarch admires the Servian reforms for their imposition of good order in government, the military and public morality, and Servius himself as the wisest, most fortunate and best of all Rome's kings.