Our own Morgan Meis in The Smart Set:
Michelangelo’s David is a large sculpture. He’s close to 17 feet tall. Since 1873, Davidhas stood on a large pedestal at the Accademia Gallery in Florence. The pedestal makes him seem even taller than his 17 feet. It is strange, really, that David should be so tall. As everybody knows, Goliath was the giant, not David. David was more or less a little guy. He was a youth, and ruddy, and of a fair countenance, as the Book of Samuel tells us. David manages to kill the giant Philistine warrior Goliath by hitting him in the head with a stone. Then David takes the giant’s sword and chops his head off. Saul, king of the Jews at the time, wonders, “Who is this kid?” That’s the biblical story of David and Goliath.
Michelangelo chose to make David — the giant-killer — into a giant himself. Mostly this has to do with accidents of history and dumb luck. There was a huge piece of marble lying around Florence in the 15th century. A couple of sculptors had tried to make a statue of it. But the block was tricky to work with, so tall and thin. No artist was yet up to the task. In 1501, Michelangelo, 26 years old at the time, said he could do the job. He promised to bring David out of the marble.
David was a special figure for Florentines. This was Italy during the Renaissance: a collection of city-states and principalities usually at war with one another. This was a time of warrior popes and family feuds that killed hundreds. The people of Florence wanted to see themselves in David. Florence was the little city that could stand up to all the others. Plus, Florence had the powerful banking family, the Medici, to deal with. The Medici were always threatening to dominate Florence, economically and politically. In the late 15th century, the city kicked the Medici out of Florence. Defying the Medici was another David-like act. Problem was, the Medici had already commissioned a sculpture of David. That’s the famous statue by Donatello. With the ousting of the Medici, the people of Florence wanted to commission their own David. They wanted to take back the symbol for themselves.
So, Michelangelo solved two problems at once. He solved the technical problem of making a giant sculpture out of a giant block of marble. And he solved the problem of political symbols by creating a statue so overwhelming to behold that David would forever be associated with the Republic of Florence. The irony is that Michelangelo had learned to sculpt under the patronage of the Medici family, but his most famous work was a repudiation of their claims over the city.
More here.