Around 1520 A.D. shoemakers began to reinforce soles with extra pieces of leather at the toe and heel parts. Sometimes pieces of cork were put in between at the heel end to make the bearer look taller. Around 1580 the first real heels were introduced. Styling changed to shoes with extended heel parts bound together on the instep with colourful laces, large and decorative bows or rosettes, made of silk and sometiomes jewelled. The search for elegant protection against the dirt of the roads continued and produced a shoe known as the "slap sole", whereby the sole was extended to the back and the high heel rested on it, thus preventing the heel from sinking into the dirt. Walking on such shoes produced a slapping sound. The development of the raised heel is probably the most momentous and far reaching change in shoe history.