Scottish Highland dancing is one of the oldest forms of folk dance, and both modern ballet and square dancing can trace their roots back to the Highlands. Dating back to the 11th or 12th century, the Highland Dances of Scotland tended to be highly athletic male celebratory dances of triumph or joy, or warrior dances performed over swords and spiked shield. According to tradition, the old kings and chiefs of Scotland used the Highland Games as a way of choosing the best men for their retinue and men at arms. Highland dancing was one of the various ways men were tested for strength, stamina, accuracy, and agility. The Scottish military regiments used to use Highland dancing as a form of training to develop stamina and agility, but this has become less common these days. Competitive Highland dancing started during the Highland revival of Victorian Britain, and was for men only. Ladies began competing only at the turn of the century. Over the centuries the dancing style has become more refined and now shares many elements from classical ballet. Although historically Highland dancing was restricted to men, today it is mostly performed by females. No matter who dances them, Highland dances require both athletic and artistic skill.