References to Friday the 13th date back to Medieval times but some believe that it was inspired by the Bible. At the Last Supper, Judas Iscariot, who went onto betray Jesus to the Romans, was the 13th person at the table, potentially inspiring further fears of the number 13. Jesus was also said to have died on a Friday — also known as Good Friday — which has potentially resulted in Christians carrying the superstition from there.