In many cultures, breaking a mirror is said to bring seven years of bad luck. This belief dates back to ancient Rome when mirrors were made of polished metal, and breaking one was believed to be a sign of impending disaster. The belief gained traction in the Middle Ages when mirrors became more common and expensive. It is thought that the reflection in the mirror was believed to hold one's soul, and breaking it would cause damage to one's essence or soul, resulting in bad luck. Even today, some people avoid breaking mirrors out of fear of attracting misfortune.