Short answers, pulled from the story.
Filippo Brunelleschi invented Renaissance architecture in the early 15th century. He began the movement by reverse-engineering the logic of the Roman Empire to create a new visual language based on symmetry, geometry, and human reason. His first major commission was the dome of Florence Cathedral, which was completed in 1436.
The dome of Florence Cathedral was completed in 1436 and served as a declaration that the age of divine mystery was over and the age of human calculation had begun. Brunelleschi solved the engineering challenge by designing a double shell with a herringbone brick pattern that required no scaffolding. This structure proved that the rules of antiquity could be applied to modern problems.
The Medici family of Florence became the primary engine of the Renaissance architectural revolution. Cosimo de' Medici commissioned Michelozzo to build the Palazzo Medici Riccardi, a fortress-like palace that used rusticated stone to project strength while maintaining a sense of classical proportion. The Medici gathered humanist scholars like Marsilio Ficino and Cristoforo Landino to create an environment where art and philosophy could merge.
Leon Battista Alberti published the first treatise on architecture, De re aedificatoria, in 1485. Alberti established the idea that the architect must be a person of great social responsibility and believed that the human form was the measure of all things. His work on the Basilica of Sant'Andrea in Mantua demonstrated how a triumphal arch motif could be used to create a dynamic facade that was both monumental and human-scaled.
The Renaissance style spread north of the Alps and to the Americas through the expansion of European empires and the use of printed books. In England, the style arrived late and was filtered through local traditions, resulting in Elizabethan prodigy houses like Longleat and Hardwick Hall. In the New World, the Renaissance style was adapted to local conditions, often resulting in a unique blend of European and indigenous traditions.