or precious stones, which would make the wall vanish. The demand for ever more stained-glass windows and the search for techniques that would support them are constant throughout the development of Gothic architecture, as is evident in the writings of Suger, who was fascinated by the mystical quality of such lighting. Renaissance During the Renaissance, Italy consisted of many states, and intense rivalry between them generated an increase in technical and artistic developments. The Medici Family, an Italian banking family and political dynasty, is famous for its financial support of Renaissance art and architecture. The period began in around 1452, when the architect and humanist Leon Battista Alberti (1404-1472) completed his treatise De Re Aedificatoria (On the Art of Building) after studying the ancient ruins of Rome and Vitruvius's De Architectura. His writings covered numerous subjects, including history, town planning, engineering, sacred geometry, humanism and philosophies of beauty, and set out the key elements of architecture and its ideal proportions. In the last decades of the 15th century, artists and architects began to visit Rome to study the ruins, especially the Colosseum and the Pantheon. They left behind precious records of their studies in the form of drawings. While humanist interest in Rome had been building up over more than a century (dating back at least to Petrarch in the 14th century), antiquarian considerations of monuments had focused on literary, epigraphic and historical information rather than on the physical remains. Although some artists and architects, such as Filippo Brunelleschi (1377-1446), Donatello (circa 1386–1466) and Leon Battista Alberti, are reported to have made studies of Roman sculpture and ruins, almost no direct evidence of this work survives. By the 1480s, prominent architects, such as Francesco di Giorgio (1439-1502) and Giuliano da Sabgallo (circa 1445–1516), were making numerous studies of ancient monuments, undertaken in ways that demonstrated that the process of transforming the model into a new design had already begun. In many cases, drawing ruins in their fragmentary state necessitated a leap of imagination, as Francesco himself readily admitted in his annotation to his reconstruction of the Campidoglio, noting 'largely imagined by me, since very little can be understood from the ruins. Soon, grand buildings were constructed in Florence using the new style, like the Pazzi Chapel (1441-1478) or the Palazzo Pitti (1458-1464). The Renaissance begun in Italy, but slowly spread to other parts of Europe, with varying interpretations. Since Renaissance