these dances were mixed, with young boys and girls dancing celebratory movements together. While the lead role was retained by male performers, structural elements began to be added in, such as circle forms and pairs moving together in formation; these developments most likely were derived from the choreographic history of ritual dances in the area. None of the dances performed by Cossacks during this time were ever recorded. Guillaume Le Vasseur de Beauplan recorded the fact that Cossacks danced in such a manner, and other historical accounts verify this. Later, Ivan Kotliarevsky and Taras Shevchenko incorporated the Hopak and dancing Cossacks into their works. However, with the destruction of the Sich in the 18th century, the dance survived only in its mixed-gender village format as a celebratory dance. Concert dance After Hopak-like dances began to be performed on stage in the 18th century in Serf and Peasant theaters, professional dramatic troupes began to incorporate this popular dance into their repertoire. These performances only incorporated the Hopak into a larger opus, such as Kotliarevsky's operetta Natalka Poltavka. It was the pioneering work of a performer in a dramatic ensemble, the ethnochoreologist Vasyl Verkhovynets, in the early 20th century, that enable the dance to develop into its current format. Verkhovynets' initial work entailed gathering authentic village steps throughout central Ukraine and constructing dances which more accurately represented the Ukrainian cultural tradition. His break-through, however, was demonstrating that staged Ukrainian dance could exist as a distinct performing art, in the form of concert dance. He and his disciple Vasyl Avramenko began staging performances throughout western Ukraine, forming troupes of dancers in village after village. In the spring of 1935, the All-Union Organization of Cultural Relations with Foreign Countries agreed to send a delegation to the upcoming First International Festival of the Folk Dance in London. Verkhovynets worked with Leonid Zhukov of the T. Shevchenko Kyiv Opera and Ballet, and professional dancers from both the Kyiv and Kharkiv Opera houses, on constructing a suite to represent the Ukrainian SSR. For his part, Verkhovynets choreographed what became known as the "London Hopak" (, translit. londonskiy hopak): this was a 3-part dance, consisting of a men's dance (much like the original Kozak dance), a second, slower segment danced only by women, and finally a rousing closing with both male and female dancers sharing the stage. This dance, along with Zhukov's addition, won the first prize at