Originally believed to have arisen in ancient Greece, internal shutters may be used to keep homes cold or warm and safe because there was no glass at the time.
The houses with strong shutters that often closed with a wide iron bar for safety were often growing in medieval Europe. Shuttercraft Cambridge offers excellent info on this.
Glass had been introduced by Tudor and Elizabethan times, but it was still very expensive, so shutters continued to be in use; sometimes windows were half glazed with solid shutters beneath the sash. When glass became more widely available shutters became less common but in many countries where humid environment did not match curtains this can still be seen in Greece they also substituted curtains.
Increasingly, during the 15th century fixed shutters were supplemented with hinged glass windows and shutters began to be used merely for decoration. Decorative woodwork such as internal window shutters continued to be popular through the 18th century, but it wasn’t until Victorian times that outdoor shutters began to become common, by that time window recesses were so wide that outside shutters couldn’t be accessed from the inside for shutting at night.
The Georgians made shutters even more common, their new homes had regular shutters, and they were known as British traditional architecture. The elegant houses in Charleston, South Carolina are perfect representations of this period with both inner and external shutters.
Today shutters are used more often on the outside of buildings and are used for both decoration and protection. Generally, the internal shutters are made of wood and built in a traditional style that is both elegant and helps you to monitor the amount of light entering a space effectively. Since the elements are held well-clear, very little maintenance is needed for the internal shutters.