Before becoming Pope, Pius II was Bishop of Siena. He was consecrated Bishop in 1450.
After becoming Pope, he elevated Siena to an Archdiocese on 23rd April 1459.
He appointed his nephew Francesco Todeschini Piccolomini (later Pius III) to be the first Archbishop of Siena and on 5 March, 1460, cardinal deacon with the title of S. Eustachio. Pius III wassucceeded in 1503 by his nephew Cardinal Giovanni Todeschini.
Pius II established and fostered an important power base for himself and his family in Siena.
As can be seen from the Commentaries, Pius II did not establish a hegemony over Siena.
In part, this was due to the history of Siena.
By 1115, there already existed municipal government within Siena.
In 1277 the Guelphs acquired control of the municipal government.
The Guelph Government of the "Fifteen", instituted in 1282, lasted for seventy years.
During this period occurred the war against the Bishop of Arezzo, head of the Ghibellines, who was conquered at Pieve al Toppo. Internal discords among the principal families, the recurrence in Siena of the conflicts between the Bianchi (whites) and Neri (blacks), the seditions of the butchers, doctors, and notaries, fomented by the nobles excluded from the government, failed to displace the Guelph merchants.
It required the Great Pestilence of 1348, with its 30,000 victims in the city, and the advent of Emperor Charles IV to effect a change in the government.
In 1355 the nobles and the common people rose in revolt, and instituted a mixed government of twelve plebeians and twelve nobles with four hundred councillors. But this lasted only a short time; in 1368 three changes were effected, and the whole year of 1369 was saddened by revolts and slaughter. The arbitration of Florence was of little avail.
To these tumults and constitutional conspiracies within the city was added (1387) the rebellion of Montepulciano, fomented by Florence. A war with Florence arose in consequence, in which the Sienese had as an ally Gian Galeazzo Visconti, proclaimed in 1399 lord of Siena. But in 1404 they deserted Visconti, made peace with Florence, to whom Montepulciano was abandoned, and constituted a new government.
From 1407-13 Siena was repeatedly assaulted by King Ladislaus of Naples, on account of its adhesion to the "Conciliabulum" of Pisa.
There was relative domestic stability in Siena between 1413 and about 1480. Following the brief spell of Giangaleazzo Visconti's control of the city between 1399 and 1403, Siena was governed by what Mario Ascheri and Petra Pertici have described as a "governo trinario," a three-party coalition that united the interests of three of the city's five sociopolitical parties (the so-called Monti). This revitalized republican government provided the patronage conditions for a series of commissions that embellished the prime sites of civic government and worship, such as the Palazzo Pubblico and the Duomo.
With the notable exceptions of an attempted coup led by Antonio di Cecco Rosso Petrucci in 1456 and Pope Pius II `s demands for the readmittance of the excluded noble families to government between 1458 and 1464, Siena's internal situation remained unaltered until the 1480s, when major institutional changes followed factional disputes and the breakup of Monti coalitions.
In 1480 on the accession of new tumults over the right to participate in the government, Pandolfo Petrucci acquired the upper hand, and in 1487 instituted a new and absolute government.
Pius II made three visits to Siena in February 1459, January-September 1460, and May 1464. The visits coincided with frenetic building activity and maintenance of the city fabric. To this end, not only were all butchers forced to relocate their businesses out from the city center to the bottom of the hill of Fontebranda, but a series of restrictions were also introduced to control the trades plied on the Campo and along the Strada Romana.
Family loggias were sites of clan interaction, where familial cohesion was displayed by architectural prominence and the widening of the street in front of them. Other noble families' palaces along the Strada Romana, such as those of the Salimbeni and Tolomei, also faced onto piazzas, which served to extend the shared family space of ground-floor loggias. Noble family loggias appear to have provided the model for the Piccolomini's choices around the Piazza Piccolomini from December 1459, when Pius II's palace-loggia complex was inaugurated.
A combination of private palace space for immediate family and separate shared loggia space for the larger clan was planned, similar to the design Giovanni Rucellai had adopted in Florence around the same time. Pius financed the initiation of a project whose object was to underline his family's achievement using sophisticated all'antica style without abandoning a preexisting luxurious palace-loggia type.
Prior even to his election as pope, Aeneas Silvius Piccolomini paid for the restoration of the district church of S. Martino, which was reconsecrated on August 10, 1458.
Pius's objective was accomplished through making the most of previously owned Piccolomini property around the Piazza Piccolomini and judicious choices in the arrangement of newly constructed buildings around the site
Original plans for the loggia provided for its alignment with the church, although the unwillingness of the schoolmaster Giovanni di Guccino to sell his school to the Piccolomini prevented this solution.
The classicizing three-bay arcade was constructed with marble columns and all'antica capitals that support a high attic bearing the Piccolomini arms and the inlaid bronze inscription PIUS II PONTIFEX MAXIMUS GENTILIBUS SUIS PICCOLOMINEIS (Pope Pius II for his Piccolomini family).
The loggia was oriented not inward, to form an enclosed, semiprivate, Piccolomini space, but faced north, its extent and interior visible from some distance away along the Strada Romana.
As if to confirm the significance of the Strada Romana viewpoint, not only were the inscription and emblazoned arms placed on the main facade, but also the most richly ornamented aspect of the loggia's bench faced neither the piazza nor the interior space of the loggia but the Strada Romana itself. The bench, prominently visible at eye level to all passersby, was decorated with a series of seven different sculpted and painted (now worn off) Piccolomini coats of arms, each of them proclaiming the status achieved by Pius and his family.
Opposite the loggia and piazza stood the enormous Palazzo Piccolomini.
After tax exemptions for building materials were granted by the commune in October 1460, as much as 8,300 ducats were paid from the papal purse between January 1461 and October 1463 to acquire land needed for the palace. The design and construction of the palace proved to be a drawn-out process that outlived even Pius's nephew-Pope Pius III (1503), but its site and ornamentation with family arms again deserve some comment.
Public support for the project, perhaps also deferential to papal desires, was granted, as mentioned, with tax exemptions in 1460, and was confirmed in October 1469, when the significant concession of public land on the Campo was made to Pius's nephews Antonio and Iacomo. However the concession was not taken up.
Benefiting thus from public support, the palazzo was built on a large site, whose main facade gave onto the Strada Romana. While a balcony and small coat of arms faces onto the Campo, the palace's sophisticated architectural style, reminiscent of the Palazzo Piccolomini in Pienza, and conspicuously lavish materials were reserved for the street facade. Not only did the palace become the dominant feature of the Strada Romana south of the Croce del Travaglio, through height and mass, but it also created a natural extension of clan space beyond the Piazza and Loggia Piccolomini. This was achieved primarily by means of a bench running along the first half of the facade, which gave a public dimension to the palace. It also appears to extend the open space of the piazza to incorporate the length of the palace, which in turn acts as a visual funnel opening onto the loggia itself.