Siena - Cattedrale Metropolitana di Santa Maria Assunta

The oldest aristocratic families in Siena date their line to the Lombards' surrender in 774 to Charlemagne. At this point, Frankish overseers married into the existing Sienese nobility. Feudal power waned, however, and by the death of Countess Matilda in 1115 the border territory of the March of Tuscany which had been under the control of her family, the Canossa, broke up into several autonomous regions. This ultimately resulted in the creation of the Republic of Siena.

The Republic existed for over four hundred years, from the 12th century until 1555. In contrast to Florence, Siena was on the Ghibelline side in the dispute between the emperor and the papacy and thus received various privileges. Essentially, however, behind this conflict was an economic rivalry between the two trading cities. The Florentines were defeated at the Battle of Montaperti in 1260. During the golden age of Siena before the Black Death in 1348, the city was home to 50,000 people.

Unlike the Medici, who ruled in Florence, no family was able to establish a stable dynasty. In the War of 1551–59, the republic was defeated by Florence in alliance with the Spanish crown. In 1512 the city found itself under the protection of Charles V. The citizens rebelled against the tyranny of the Spaniards, but In 1555 Siena was taken after a long siege and two years later given as a fief to Cosimo I de Medici, under whom it became part of the Grand Duchy of Tuscany.

There was a 9th-century church with the bishop's palace at the present location. In December 1058 a synod was held in this church resulting in the election of pope Nicholas II and the deposition of the antipope Benedict X. In 1196, the cathedral masons’ guild, the Opera di Santa Maria, was put in charge of the construction of a new cathedral. About 150 years later, the church may have been completed, but a massive addition of the cathedral was planned in 1339.

It would have more than doubled the size of the structure and so it would have been larger than (old) Saint Peter in Rome. This cathedral was never completed. The construction was halted by the Black Death in 1348. Then errors in the static of the building got evident.

The west facade was begun in 1285. Giovanni Pisano as the architect. He completed the lower level by 1297 but left Siena after a quarrel with the Opera del Duomo. The work continued until 1317 but then came to a halt. Inspired by the facade of Orvieto Cathedral the work started again in 1376.