In 1173 (as the most recent historian of Florence has shown, and not in the eleventh century as formerly supposed), the second circle of walls was built, and included a much larger tract of city, though many of the churches which we have been wont to consider the most essential things in Florence stand outside them. A new Porta San Piero, just beyond the present façade of the ruined church of San Piero Maggiore, enclosed the Borgo di San Piero; thence the walls passed round to the Porta di Borgo San Lorenzo, just to the north of the present Piazza, and swept round, with two gates of minor importance, past the chief western Porta San Pancrazio or Porta San Paolo, beyond which the present Piazza di Santa Maria Novella stands, down to the Arno where there was a Porta alla Carraia, at the point where the bridge was built later. Hence a lower wall ran along the Arno, taking in the parts excluded from the older circuit down to the Ponte Vecchio. About half-way between this and the Ponte Rubaconte, the walls turned up from the Arno, with several small gates, until they reached the place where the present Piazza di Santa Croce lies--which was outside. Here, just beyond the old site of the Amphitheatre, there was a gate, after which they ran straight without gate or postern to San Piero, where they had commenced. Instead of the old Quarters, named from the gates, the city was now divided into six corresponding Sesti or sextaries; the Sesto di Porta San Piero, the Sesto still called from the old Porta del Duomo, the Sesto di Porta Pancrazio, the Sesto di San Piero Scheraggio (a church near the Palazzo Vecchio, but now totally destroyed), and the Sesto di Borgo Santissimi Apostoli--these two replacing the old Quarter of Porta Santa Maria. Across the river lay the Sesto d'Oltrarno--then for the most part unfortified. At that time the inhabitants of Oltrarno were mostly the poor and the lower classes, but not a few noble families settled there later on. The Consuls, the supreme officers of the state, were elected annually, two for each sesto, usually nobles of popular tendencies; there was a council of a hundred, elected every year, its members being mainly chosen from the Guilds as the Consuls from the Towers; and a Parliament of the people could be summoned in the Piazza. Thus the popular government was constituted.