Filippo Brunelleschi (1377-1446) was one of the foremost architects and engineers of the Italian Renaissance. He is most famous for designing and constructing the enormous dome that covers Florence's cathedral, Santa Maria del Fiore. The dome he created was an architectural and engineering feat without precedent - it was wider than any dome previously built and erected without the aid of supporting wooden framework. His dome was constructed with bricks following a double shell design he invented that gave it strength and allowed the dome to be unusually tall and wide for the time.
Brunelleschi was born in Florence in 1377 into a prosperous merchant family. Florence was a bustling commercial and artistic hub of medieval and early Renaissance Italy. From a young age Brunelleschi showed artistic promise and became skilled as a goldsmith and sculptor as well as displaying talent in mathematics, mechanics, and physics. He apprenticed first in an artisan bottega and then studied sculpture in Rome with Donatello, an influential sculptor of the early Renaissance, with whom he would remain friends for life. While Brunelleschi's primary occupations would eventually turn to architecture and engineering, his training and skill as an artisan and artist undoubtedly informed his architectural work and innovative building designs. 
After returning from Rome, Brunelleschi began entering sculpture and architecture competitions in Florence around the turn of the 15th century. One of the first and most pivotal of these was for new sets of bronze doors for the Baptistry of the Florence Cathedral in 1401. Having dedicated considerable time sculpting his entry, Brunelleschi was devastated when another sculptor's entry was selected as the winner. It was after this defeat that Brunelleschi turned his focus from sculpture to architecture. 
The pivotal commission of his career was designing the dome to cover Santa Maria del Fiore in Florence. The cathedral had been designed in the late thirteenth century in the Gothic style with a massive octagonal space to be covered by an unprecedentedly wide dome spanning nearly 150 feet. No dome of such a diameter had ever been successfully erected, and the cathedral space remained uncovered for over a century. Then in 1418 Brunelleschi won a competition to design and build the dome. However, his unique and innovative design were regarded suspiciously and it was only after he demonstrated his method using a wooden model dome that approval was granted in 1420 for construction to start.
Brunelleschi devised a distinctive double shell construction for the dome because due to its size traditional methods would require massive wooden centering frameworks to hold it in shape until the mortar dried and set. These timbers would have had to support each stone as it was precisely placed into position. Such a wooden framework would have been impractically large however. So Brunelleschi envisioned the dome as two self-supporting domes or shells, one inside the other. The shells are interlocked with sturdy stone ribs and horizontal chains encircling the dome for circumferential stability. Space between the inner and outer shells filled with light bricks relieved some of the weight projected at various points and enabled thinner walls for both shells than would otherwise be possible. The dome rose without ever needing supporting framework which would have been impossible to construct. He also invented special machines to hoist the needed building materials upwards as construction progressed ever higher.
Brunelleschi's dome was completed in 1436. His ability to vault such a wide area won him acclaim and established the dome as one of Florence's most iconic and recognizable architectural landmarks. Over a century after it first took shape as merely a gaping cathedral space and after failed attempts by other architects and engineers, Brunelleschi's innovative structural design succeeded in creating the...