The Cathedral of Siena was built between 1215 and 1263 and designed in part by Gothic master Nicola Pisano.
His son, Giovanni, drew up the plans for the lower half of the facade, begun in 1285.
The facade's upper half was added in the 14th century.

The 14th century was a time of great wealth and power for Siena,
and plans were made to expand the cathedral into a great church that would dwarf even St. Peter's in Rome.
The already-large Duomo would form just the transept of this huge cathedral.

Expansion got underway in 1339 with construction on a new nave off the Duomo's right transept.
But in 1348, the Black Death swept through the city and killed 4/5 of Siena's population.
The giant cathedral was never completed.