Leonardo da Vinci
Leonardo, born in 1452, lived his life during the High Renaissance, moreover in its center, in the northern Italian city states. Indeed, he was, to a large extent, what we now call a Renaissance man: a man with a vast array of interests and knowledge. The extent of his skills is undoubtedly the first thing that interests us. He was a painter and inventor, surely; but this is not a sufficient description. He dealt, often to a great extent, with most of the existing natural sciences (and some more or less founded). At that time he was perhaps the greatest expert in human anatomy and physiology; he gained this knowledge during the autopsies he performed at one point in his life. He invented marvelous machines - visionary and absurd. Some seem to have fallen out of the spooky (at least from today's perspective) triptych Garden of Earthly Pleasures by Leonardo's contemporary Hieronymus Bosch (whom Leonardo almost certainly never saw). He composed music.
And of course - painted. The volume of his production is in stark contrast to the fame of the author. Leonardo da Vinci is still considered one of the greatest painters of all time, but there are only fifteen works of art for which his authorship is considered indisputable (not counting the large number of drawings and sketches in his surviving notebooks)
While Michelangelo was an exception, Leonardo was notorious for not meeting deadlines and often not completing the work, lured by another contract. That was why he had so little work to do and so many sketches - of course brilliant. It is often believed that, paradoxically, his lack of education helped him to do this. Leonardo was a brilliant self-taught person. He read a lot, but in his youth he was limited to translations into Italian. He learned Latin, the language of scholars, as an adult, and apparently not quite well. He did not speak Greek, the language of top scholars.