In 'Romeo and Juliet', Shakespeare makes Mercutio speak about Queen Mab, "the fairies' midwife". He describes her carriage as "an empty hazel-nut" with a cover made from "the wings of grasshoppers" and traces of "the smallest spider's web", drawn by a gnat.

Quite small, then.

Yet in 'A Midsummer Night's Dream' the fairies are of equal stature with the humans lost in the wood, opening the way for misunderstandings and mischief.

So, how tall are fairies: six feet, six inches, or six millimetres?

It depends largely on your source. If you are reading 'fairytales' of the last two hundred years or so intended for children, then a miniature ballerina is probably the image. But delve into folklore centuries before that, across Europe and much of the rest of the world, and fairies by whatever name are seen as a race sufficiently similar to us to be confused with family, neighbours and strangers on the road.

And they certainly don't have wings; not even Queen Mab.

The word fairy is derived from Middle English, and can mean both the individual and the realm, although when the realm it is often spelled Faerie. And fairies go by many other names too: sprites, brownies, kelpies, elves, selkies – who were shape-shifters and appeared as seals – and more. They have been variously believed to be angels, demons, ghosts or the remnants of earlier tribes driven out by settlers and dwelling in the hollow hills.

Legends abound of mortal men entrapped by the fairy queen and kept underground while centuries passed; of midwives kidnapped and illuded to birth a fairy child; of human babies stolen or exchanged for changeling fairy infants; of fairy wives and fairy tricksters and fairy harbingers of doom. All rely on the world of Faerie being close by and yet unreachable, known of and yet invisible. Most – though not all – are highly unlikely

A World Denied:

Invisible Worlds