YO-YO is known as the second oldest toy (the first being dolls). The earliest records in history books appeared in Greece before 500 AD. Such a ceramic jar is still preserved in the National Museum in Athens. The figure on the jar is holding the ancestor of Youyou. The materials of this kind of toys are wood, metal or colored clay, and the patterns are mostly images of gods. YO-YO comes from the Filipino Tagalog, which means "come back" or "go back". In 1500 AD, Filipino hunting people hung heavy objects such as dried fish and shells on the front end of a 20-foot (about 6-meter) rope as a tool for hunting animals and fighting. It is said that children of hunting people made this tool into smaller models and began to play with it. This is the origin of Yoyo. In 1700 AD, Yoyo spread from China east to Nagasaki, Japan, west to India, and from India to Europe. In Japan, Yoyo is vividly called "unicycle" or "money wheel" and is very popular among young people. At the beginning of the 18th century, yo-yos were widely popular in the UK as "Prince's Treasure" and in France as "Norman yo-yos". They were especially popular among the upper classes in France and Britain, and were regarded by the nobles as a fashionable and noble toy. . In the International Art Museum, you can also see an oil painting with the theme of King George IV playing YO-YO, which shows the popularity of YO-YO in Europe at that time. The name YO-YO first appeared in 1920. A Filipino named Pedro Flores introduced YO-YO to the United States. At that time, he was working in a hotel and picked it up to play in his spare time. He later founded his own toy company, Flores YoYo Company. In 1929, after seeing the potential of YO-YO, Duncan established a company with the same name (DUNCAN) and began to train demonstrators, perform everywhere, guide people to play YO-YO, and hold competitions. In 1950, Duncan produced the first rubber YO-YO and butterfly-shaped YO-YO. The YO-YO craze started in 1962, when Duncan popularized the YO-YO show on television. In November 1965, Duncan Company could no longer sustain itself and declared bankruptcy. Taken over by the Flambeau Company, 11 types of Duncan YO-YO balls are still popular today.