<P> Halloween costumes are costumes worn on or around Halloween, a festival which falls on October 31 . An early reference to wearing costumes at Halloween comes from Scotland in 1585, but they may pre-date this . There are many references to the custom during the 18th and 19th centuries in the Celtic countries of Scotland, Ireland, Mann and Wales . It has been suggested that the custom comes from the Celtic festivals of Samhain and Calan Gaeaf, or from the practise of "souling" during the Christian observance of Allhallowtide . Wearing costumes and mumming has long been associated with festivals at other times of the year, such as on Christmas . Halloween costumes are traditionally based on frightening supernatural or folkloric beings . However, by the 1930s costumes based on characters in mass media such as film, literature, and radio were popular . Halloween costumes have tended to be worn mainly by young people, but since the mid-20th century they have been increasingly worn by adults also . </P> <P> The wearing of costumes at Halloween may come from the belief that supernatural beings, or the souls of the dead, roamed the earth at this time . </P>

When did costumes become an essential part of halloween
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