Pair skating is a figure skating discipline defined by the International Skating Union (ISU) as "the skating of two persons in unison who perform their movements in such harmony with each other as to give the impression of genuine Pair Skating as compared with independent Single Skating". The ISU also states that a pairs team must consist of "one Lady and one Man". Pair skating, along with men's and women's single skating, has been an Olympic discipline since figure skating, the oldest Winter Olympic sport, was introduced at the 1908 Summer Olympics in London. The ISU World Figure Skating Championships introduced pair skating in 1908.