This is based on a medieval French tale in the Arthurian cycle, the Lay of Melion, one of the best of the lesser known Arthurian romances. What I have here is little more than a rough draft summary of the story; the original has some splendid passages in which you can tell that the poet enjoyed the challenge of conveying what it would be like to be a man in wolf's form. The story goes back at least to the twelfth or thirteenth century. You can tell it is quite early from the prominence of Sir Yder, an extremely popular character in early Arthurian legend who almost drops out completely much later; it is sometimes thought that this may be because French authors began drawing on his stories to write about Sir Lancelot.
In Arthur's day there was a knight,
Melion was his noble name,
of venerable family
from strange realms distant and foreign,
and he held from them a fair heirloom,
a magical ring, truly old,
by which he could take a wolf's form,
swift, gray of hame, with teeth most fierce.
He vowed never to love a maid
who had loved any other man;
thenceforth no maid would speak to him,
and his spirit became heavy.
To the country Melion went,
hunting, as he loved, in the woods.
Greatest of hunters he became,
swift of foot after bird and beast,
and one day, hunting a great stag,
in a small glade to rest he stopped,
and saw a maid on a palfrey,
fair of dress and her eyes perfect;
she spoke to him, and he to her.
She said she had loved none but him;
Melion kissed her thirty times.
By such things are young men taken!
Swift and joyful was their wedding;
two sons they had, and joy a while.
But on a time they hunted stag
and caught sight of one swift and strong,
which the lady begged him capture
lest she die, for its meat craving.
He showed her the marvelous ring.
Two were its stones, one white, one red;
the white gave the form of a wolf,
and the red restored from the white,
each by being held to the head;
and he gave it to her to hold.
"Know that you hold my life, my death;
without this ring, I am but doomed,
and am a wolf for all my days.'
Thus a man's trust may run deeply.
Melion beckoned to his squire,
and they removed his hunting suit.
His lady touched him with the ring,
and he became a wolf and ran,
pursuing the scent of the stag.
Then the lady said to the squire,
"Let him hunt,' and they from there fled,
and to Ireland they both did fare.
Melion the captured stag
returned to his lady and squire,
but only their scent was left behind.
He tracked them to a wooden boat,
and he sneaked aboard in dark night,
and huddled down, and made no noise.
When to Ireland the ship had come,
he leaped out; the sailors clamored,
almost caught him, but he ran free,
ran across tall hills and wide fields,
and lived his life an outlaw wolf
until he could confront his wife.
Melion wandered through wide forest,
stealing sheep and cows from the fields,
and fell in with ten wolves, a pack,
and they were by him persuaded;
together they through the woods roamed,
and did all things under his rule.
For his wife was the king's daughter,
and to draw her out took sly deeds.
A great host the king did gather
to take the wolves in the greenwood.
The wolves, surprised, were torn by dogs;
Melion alone escaped death.
Reason's power saved him from harm,
but a wolf has little to help.
Alone again, Melion grieved,
for his loss and his hurt were great.
But in that day came Arthur king
to make a treaty, end conflict.
Melion saw their shields shining,
hanging like sigils on their ship.
Swiftly he sped, wolf Melion,
praying in his heart for mercy.
Soon he came to the old castle
where rested the knights of the king.
Strong were the guards, and fierce their swords,
and wolf Melion could not speak.
Among them he ran, risking death,
and before the king he knelt down.
Arthur marveled at his tameness,
and bade the wolf be well treated.
Soon the king of Ireland joined them,
with many a courtier and thane,
bringing joy and peace and honor.
The wolf trotted by Arthur's horse,
and they came to a great palace
and at table took their places.
Light was in the air, and gladness;
the food and folk were glorious.
Melion at Arthur's feet sat--
until he saw nearby the squire.
Fury took him, he leaped with speed,
and the squire by shoulder he seized.
Surely the squire would have been killed,
if not for the knights of the kings!
Great was the noise and commotion;
they came at the wolf with cudgels.
But Arthur cried, "This wolf is mine!
Do not harm him for love of me!"
Then Sir Yder said, "This is strange;
the wolf has only this man seized.
Surely there must be a reason!"
Then Arthur replied, "Yes, you are right.
Squire! You will confess your dark deeds,
or you will at once surely die!"
Wolf Melion gripped the traitor;
the squire begged for mercy and told the tale,
how he fled with his lord's lady
and in wolfish form his lord left.
The Irish king went, grim and dark,
and brought the ring from his daughter.
The wolf was glad to see the ring,
deep in his spirit he rejoiced;
before the king on knees he fell,
and touched his tongue to Arthur's feet.
Almost King Arthur used the ring!
But Sir Gawain suddenly rose:
"Do not do it, my uncle good,
not before these noble folk and great;
take him to a private chamber
that unashamed he may be changed!"
With Yder and Gawain, Arthur
took the wolf to a different room.
The ring was touched to Melion,
and the wolf's head became a man's,
and, now a man, he was naked,
and with gladness he felt as new.
He was wrapped in Arthur's own cloak;
the servants were sent to get clothes.
The court at Melion marveled,
pitying his great misfortune.
The Irish king brought his daughter,
knowing that she might be destroyed.
Melion said, "Use the ring's stone."
But Arthur said, "Recall your sons."
And for her life the Irish begged,
and all of King Arthur's barons,
and for he was a man, not wolf,
Sir Melion with mercy wept.
In Ireland he left her and sailed
to his own home across the sea.
Thereafter Melion would say,
"However fair your love may seem,
never in all things trust your wife;
she may prefer you as a wolf."
And thus you have heard my whole tale;
all good people say it is true.