The first stone for the Basilica di Santa Maria del Fiore (Duomo) was laid in 1296. However, 122 years later in 1418 there was still no firm plan for the dome. Filippo Brunelleschi and Lorenzo Ghiberti (who would go on to create artistically-significant baptistery doors) competed for the commission to design and construct the dome. Because Florentine city fathers ruled out the use of buttresses commonly used to transfer the weight of a large cathedral safely to ground, it was not clear that a dome could be constructed to span such a space without collapsing of its own weight. Using the study of other domes, most notably the concrete dome that covers Rome's Pantheon, together with mathematical genius, intuition and clever design of the necessary machinery, Brunelleschi overcame each of the many formidable challenges to create the dome you see here, containing over four million bricks, and to this day the largest concrete vaulted dome ever built.