Merry Vernal Equinox!
The midpoint in the year, between Winter and Summer.

In the British television series Robin of Sherwood, the shaman/god Herne tells Robin Hood that the mystical "Powers of Light and Darkness" are with him. At the Vernal Equinox, the natural powers of Light and Darkness are perfectly balanced, with the day equal in length to the night. The Wheel of the Year is poised halfway between the Winter Solstice and the Summer Solstice. The sun is gaining in strength, however, and the earth is beginning to warm. Winter is easing its grip on the land, and the first shoots of green begin to appear, signifying Spring, and heralding the Summer soon to follow.

In his masterpiece, The Golden Bough, Sir James Frazer recorded several examples of a springtime "Battle of Summer and Winter" that was acted out in Sweden and parts of Germany. In this theatrical ritual, a mock combat was staged in which a young man representing Summer, clad in greenery or finery, fought and defeated an opponent representing Winter, clad either in furs or straw. The ritual performance took place anytime from Shrove Tuesday, to the fourth Sunday of Lent, to May Day, yet these varying dates may perhaps be later Christian approximations to the timing of an original pagan spring festival, possibly held at the Vernal Equinox, the natural midpoint between Summer and Winter.

The mediaeval ballad of Robin Hood and Guy of Gisborne, which scholars believe "may well be one of the earliest of all the Robin Hood ballads" appears to be, in part, a literary echo of the same ritual "Battle of Summer and Winter" carried out in the Germanic folk springtime pageants, with Robin taking the part of Summer, and Guy the part of Winter. As Robin Hood scholars Stephen Knight and Thomas Ohlgren point out, "The whole encounter [between Robin and Guy] has elements of natural myth about it, suggested rather than expressed."

The ballad's opening verse sets the action in either late spring or early summer, when the trees have fully leafed out:

"When shawes beene sheene and shradds full fayre,
[When woods are bright, and branches full fair]
And leeves both large and longe,
Itt is merry, walking in the fayre forrest,
To heare the small birds singe."

Robin was commonly designated as the Summer King in the folk pageantry of the English May Games, and this association would be strong in the minds of the ballad's audience. Moreover, Robin clearly dresses the part of Summer in the ballad, for we are told that, in preparing to meet Guy, both he and Little John "cast on their gowne of greene".

Guy of Gisborne, however, is more fantastically attired in a horse-hide, complete with the animal's head and tail:

"And he was cladd in his capull-hyde,
Topp, and tayle, and mayne.
"

As noted by Knight and Ohlgren, this horse-hide is "more like a ritual costume than a disguise". And indeed, clad in this animal skin, Guy closely resembles the actors dressed in fur who portrayed Winter in the Germanic mock battles of springtime. The identification of Guy with the personified Winter thus provides a logical explanation for the otherwise bizarre and mysterious detail of his wearing a horse-hide in the ballad.

Sources

"Battle of Summer and Winter" from Sir James Frazer's The Golden Bough

The ballad of Robin Hood and Guy of Gisborne

Knight and Ohlgren's introduction to the ballad

Merry Springtime Blessings

from Hester @