the first of Etruscan birth. After immigrating to Rome, he gained favor with Ancus, who later adopted him as son. Upon ascending the throne, he waged wars against the Sabines and Etruscans, doubling the size of Rome and bringing great treasures to the city. To accommodate the influx of population, the Aventine and Caelian hills were populated. One of his first reforms was to add 100 new members to the Senate from the conquered Etruscan tribes, bringing the total number of senators to 200. He used the treasures Rome had acquired from the conquests to build great monuments for Rome. Among these were Rome's great sewer systems, the Cloaca Maxima, which he used to drain the swamp-like area between the Seven Hills of Rome. In its place, he began construction on the Roman Forum. He also founded the Roman games. Priscus initiated great building projects, including the city's first bridge, the Pons Sublicius. The most famous is the Circus Maximus, a giant stadium for chariot races. After that, he started the building of the temple-fortress to the god Jupiter on the Capitoline Hill. However, before it was completed, he was killed by a son of Ancus Marcius, after 38 years as king. His reign is best remembered for introducing the Roman symbols of military and civil offices, and the Roman triumph, being the first Roman to celebrate one. Servius Tullius Priscus was succeeded by his son-in-law Servius Tullius, Rome's second king of Etruscan birth, and the son of a slave. Like his father-in-law, Servius fought successful wars against the Etruscans. He used the booty to build the first wall all around the Seven Hills of Rome, the pomerium. He also reorganized the army. Servius Tullius instituted a new constitution, further developing the citizen classes. He instituted Rome's first census, which divided the population into five economic classes, and formed the Centuriate Assembly. He used the census to divide the population into four urban tribes based on location, thus establishing the Tribal Assembly. He also oversaw the construction of the Temple of Diana on the Aventine Hill. Servius’ reforms made a big change in Roman life: voting rights based on socio-economic status, favouring elites. However, over time, Servius increasingly favoured the poor in order to gain support from plebeians, often at the expense of patricians. After a 44-year reign, Servius was killed in a conspiracy by his daughter Tullia and her