Fear of the number 13, known as "triskaidekaphobia," has its origins in Norse mythology. In a well-known tale, 12 gods were invited to dine at Valhalla, a magnificent banquet hall in Asgard, the city of the gods. Loki, the god of strife and evil, crashed the party, raising the number of attendees to 13. The other gods tried to kick Loki out, and in the struggle that ensued, Balder, the favorite among them, was killed.
of 13-member dinner parties, and dislike of the number 13
itself, spread south to the rest of Europe. It was reinforced in
the Christian era by the story of the Last Supper, at which
Judas, the disciple who betrayed Jesus, was the thirteenth guest
at the table. See also LINK