Da Vinci was already alive when the Eastern Roman Empire fell
Some historical periods are hard to put into context since they encompass centuries. One example is the Renaissance. We know it as a time of artistic and engineering splendor during which several Italians became centers of wealth and power in Europe.
The period covers the 15th and 16th centuries, which is a long time. The Eastern Roman Empire fell in 1453, a mere year after Leonardo Da Vinci was born. This shows how events we might believe happened far apart actually unfolded quite close together.