Although the origins of the first Franciscan oratory are still lost in the mists of time, the construction of the new Basilica of Santa Croce is well documented and was officially started on May 3rd 1294, when the architect, Arnolfo di Cambio, laid the first stone of what was to become a masterpiece of Gothic art. His design was based on spatial grandiosity, with the structural elements carried out with rational clarity and sobriety.

It is built on the plan of an Egyptian cross (in the shape of a T), with the interior divided into three naves (114,45 metres), a chancel and a transept full of chapels whose patronage was reserved for the most illustrious families in this quarter of the city: the Bardi and Peruzzi families were the foremost, but there were also the Tosinghi, Pulci, Rinuccini and Alberti families. The walls of these chapels and the entire church were immediately covered in frescoes by Giotto and his school, who turned the basilica into a museum of Florentine Trecento painting. The same artists also designed the wonderful luminous stained glass windows.

When at last the church was finished in 1442, it was consacrated by Pope Eugene IV. The facade was left undecorated; in fact it was not completed until 1857-63, more or less at the same time as the Belltower was rebuilt to replace the original one which had been struck by lightning.