PART I
The Ancient Realm
I am almost certain every child, at some point or another, during the fancies of youth, has the mind to wonder and the heart to wish they could fly like a bird, or run like a horse, or climb like a lynx! How limitless would the world seem if we could bound over any barrier like a deer on the run, or escape in flight all that troubles us on this lowly earth?
Here's a wonder, the more we observe in the majesty and magnificence of nature, the more we want to be a part of it. But, as youth gives way to the sage years, we experience the fading away of childish dreams and begin to realize that there is a real danger hidden beneath all that mystical beauty. There is a power in nature that is always moving and never seen... Nature then, is a thing to be feared or shunned, and even in its smallest forms it begins to annoy and hinder our ways.

It is said that the trees themselves walked like men in those days, and the animals were far more peaceable and communicative than they are today. But, that was before the coming of shadow and men into these northern lands to build their ships, during an age they called prosperity. During this time, the beasts were driven and hunted, scattered to the four corners of the realm, all while mankind expanded their territory and fought their great wars.
The forest was cut down, by acres and by miles, until only a minuscule fraction remained. Now only small scattered groves are left of what once was a massive woodland. The largest patches of which today are so insignificant that only two this side of the Misty Mountains are named; Eryn Vorn, and what is called by the smaller folk, the Old Forest.

As time passed, man was consumed by his own affairs and disputations, he was wrapped up in his own fears and passions. Evil brewed in secret, and while messages were sent in the forms of the birds and the beasts of prey, not many were heeded. Some creatures, such as the White Stag, brought tidings of great good to the eyes and ears of men, which were seldom disregarded. Others, however, came only as heralds of great evil, and were written into history as the ill omens that precede woe and misfortune throughout all of legend.
The truth remained that the beasts were succumbing to the influence of darkness. The animals began to prey on the children of men, and all innocence was smitten in the battle between the forces of good and evil.
The untamed wilderness became a savage, merciless land filled with cruel inhabitants; A realm where none could walk safely.

PART II
A More Recent History
Now, surely that is not the end of the tale, for not all creatures fell away and became the servants of evil. History, as we have seen, oft finds the tales of beasts entwined in the stories of men; Such as in the relations of Erebor, where the Dwarves knew the allegiance of the Ravens under Carc, the Raven King. And, before the Great Worm, even Smaug the Terrible, came from the mountains and desolated the lands surrounding the Dwarven kingdom, taking their palaces to be his own, the Thrushes of the woodland had already taught their speech to the Men of that land.
So we see that the small beasts of the realm have had a great impact on the stories which are told of great evil being overthrown. It was so with Smaug when the Thrush knocked and the least suspected creature of all came walking unseen into his fortress: The Hobbit, Bilbo Baggins, was in the end the one who discovered the weakness in the dragon's armor, and by him was it made known to the Thrush, who in turn brought word to the arrow of Bard - and in fiery ruin the terrible worm was felled!
But Bilbo and the Dwarves of Thorin Oakenshield's company were often aided by such unusual means, and they would not likely have accomplished their quest if not for the help that came at the most needed time and from the most unlikely places - Unlikely it was indeed in the Great Beorn's time, that he would house thirteen dwarfs, one hobbit, and a wizard all in the same evening!
Though Radagast the Brown was known to Beorn, and was friend to his house, it was the wizard Gandalf, then called the Grey, that led Oakenshield's company to the Great Hall to take refuge there. And, when the tale was cleverly unfolded, and later proved, the dwarves of Erebor knew the friendship of Beorn the Great for as long as he lived.
Often in the succeeding years the dwarves of that company returned to Beorn's house again, and, even before in the Battle of Five Armies, did he play a significant part.

Though I shall not tell how bears and men came to walk together, for that is a tale to be sung of in the Hall of Beorn alone. Yet it was at the time of the great
destruction and mustering of the shadows that my ancestors came over
to inherit the white peaks in the eastern mountains, where there they dwelt for years
unnumbered in the mountain country and no stories are had in the languages of men
as to how their generations fared. But, after a time, the giants came to
the mountains, and then came also the orcs and the goblins... thus it is. However, I shall not relate that tale, as the
story of the great battles that were fought and the carnage reaped need
not be spoken here - let it only be said that everlasting hatred
was kindled at that time between my folk and the goblins of the Misty
Mountains.
PART III
From the Past to the Present

Thus the children of Beorn have grown great and numerous, having adapted to different ways. But whether they have returned to their origin in the wilderness, or have chosen to live amongst man, the presence of Beorn's children will always be felt, in whichever place they reside. And, perhaps, if you look very closely, you might even come to recognize them - be it in the forests and mountains, or the lively markets and homes of men.
~Ragnböurg