As soon as he became Pope, he decided to completely transform his native city into an ideal Renaissance town, even more beautiful than Siena, starting with its name.
So, Corsignano was then called Pienza ( from Pius).
Meant as a retreat from Rome, it represents the first application of humanist urban planning concepts, creating an impetus for planning that was adopted in other Italian towns and cities and eventually spread to other European centres.
Pius II chose the architect Bernardo Rossellino, who may have worked with the humanist and architect Leon Battista Alberti, though there are no documents to prove it for sure.
Alberti was in the employ of the Papal Curia at the time and served as an advisor to Pope Pius II.
The construction started in 1459. Pope Pius II consecrated the Duomo on August 29, 1462, during the long summer Pope visit.
During his journey there, the Pope lived in the Papal Palace there, the Palazzo Piccolomini.Neither the architect Rossellino nor the Pope could enjoy Pienza for a long time.They both died in 1464, three months apart from each other.
With them, it died the wish of developing the rebuilding of Pienza.
A century later, Michelangelo will be inspired by the perspective of the main square of Pienza to design a masterpiece in architecture, famous all over the world: the Capitoline square in Rome Italy.