The history of artificial beings is a fascinating one, and not a tale that has its earliest roots in the sterile labs of robotics facilities, either. Rather it all began in times of yore, back when the Earth was unexplored, and humanity as a race was young and naive. The forests were homes to mystical creatures, the gods performed the functions of physical forces, and magic was the primary force of both construction and destruction, rather than technology.
The knowledge of how to create a moving, functioning creature was not a secret amongst those with arcane ability. For eons the mages formed homunculi and constructs of rock or metal, simple things that lumbered on two feet and obeyed their summoner's commands. These basic conjurations were easy to control but not overly helpful, as they were painfully literal in their interpretation of orders, and did not think outside the box in the least. The answer? More complex, advanced creations, of course! The wizards of the time worked to push their art forward, some calling up more accurate representations of human beings, whether it be physically realistic, to the point of being indistinguishable from real people, or mentally complex, so that they thought and felt and believed and loved, just like mankind.
On the other end of the spectrum, there were warlocks who sought to make their constructs larger, and more powerful, larger than life beings that loomed above their masters. At first they were used for raising buildings and excavating mines, but it wasn't long before they were put to use satisfying the most basic human instinct of all: conflict. Battle golems rushed the opposing lines to fight and kill with bladed arms. Siege golems lumbered across the battlefield, hurtling giant rocks at enemy armies and tearing down the walls of hostile fortifications. Many a fight was determined not by how many platoons an army fielded, but rather how powerful their compliment of mages was.
The natural evolution (and highest peak) of all this magical mastery was the creation of Fortress golems, massive constructs of flesh and stone, as much a creature of combat and offense as a symbol of protection and defense. With reinforced walls and stable platforms, these artificial beings could house an entire detachment of archers equipped with deadly longbows and crossbows, and defensive troops with swords and pikes to fend off any would-be boarders. Just a single stomp of their enormous feet is enough to take out whole squads, and their gloved fists can tear down castle walls with merely a few punches.
The only thing that stops these lumbering beasts from dominating the field of war is how prohibitively expensive, enormously difficult, and extremely draining they are to create. An entire nation's population of magicians and sorcerers and wizards must devote itself to the formation of these humongous weapons, and many weaker or less trained individuals die in the process. The materials required to erect such a massive project could create three royal castles easily, or hundreds of smaller field bases and outposts. Even should all this be arranged, the process can still fail if the requisite amount of attention to the summoning effort is not maintained, creating a flawed product or worse, an uncontrolled Fortress golem. For that reason, all constructs of this size class were formed with built-in weakness, or pre-programmed halt functions, or at the very least a limited lifetime, with a need for maintenance or magical recharging to continue functioning.
All, that is, but one. The initial Fortress golem, the Alpha, as it were, was still in its testing phases, only because no one had ever attempted anything so audacious before. Without any knowledge of how much it would cost, or how best to proceed, the first Fortress golem was as much a work of art as it was an arcane experiment, and a military revolution. No expense was spared in ensuring it was lifelike even for a synthetic creature, a gigantic being that lived and breathed much like any other human, only at a much larger scale. It still feeds off of ambient mana and essence, like any other golem (albeit at a greater scale, sometimes putting nearby fauna and flora in danger after an extended period of time), but it is, for all intents and purposes, alive.
And one other thing: it is free. A creature that large takes orders from no man, not even the hand that forged it. And so the Alpha wandered away, simple as that, ignoring all commands to stop, the horde of mounted cavalry chasing after her, the frantic soldiers jumping off her battlements. She marched away and into the woods, to disappear off the face of history and into the realm of legend.
Rough size comparison picture (sorry for sketchiness)
