The first written records of humankind provide evidence for the existence of toys as children's playthings back to prehistoric times. The earliest toys were made of basic materials, such as wooden sticks, clay, terracotta and rocks; since the 20th century, toys have widely been produced using plastic. Although the materials used for toys have drastically changed over thousands of years, the trend for toys imitating adult life has remained a constant. This is demonstrated by the popularity of model cars from the 1900s onwards, corresponding with the rise of the automobile, which brought success to brands such as Dinky Toys and Corgi Toys. Since the launch of the iconic Barbie in 1959, toy dolls have dominated the market, with original models becoming collectors' items. Undoubtedly, the Star Wars franchise released some of the most covetable and collectibly toys during the 1970s and 1980s, with some items being sold for thousands by dealers and at auction.