Ravens in a snowstorm near Kuhmo, Finland

© Frans Lemmens/Alam

Unlucky for some

For the superstitious, ravens have long been considered a bird of ill omen although here in the UK, others are rather keen to keep them around. One legend has it that the Tower of London and the kingdom will fall, if its resident ravens ever leave – something thought to date back more than 300 years to the reign of Charles II. To others though, ravens are just a bunch of birds and Friday the 13th is just another day.

The notion of Friday the 13th as doubly jinxed is only a century or two old, but Friday and the number 13 individually have long been thought of as unlucky. Old Norse and Christian traditions both tell of suppers spoiled by a malign 13th guest (Loki the trickster and Judas the betrayer, respectively), while nautical lore says that a voyage that begins on a Friday is doomed to sink.

Combining 13 and Friday to suggest the mother of all bad days goes back to the 1800s, although some historians say it really caught on after the 1907 novel Friday the 13th, in which a conniving stockbroker incites a Wall Street crash. Whether you call this bad luck stuff bona fide or baloney, there's no harm in watching your step a little more closely today. Touch wood.