The city of Zaun is a place where both magic and science have gone awry. The unchecked nature of experimentation has taken its toll on the city. However, Zaun's lenient restrictions allow their researchers and inventors the leeway to push the bounds of science at an accelerated rate, for better or worse. It was under these conditions that a team of doctoral students from Zaun's College of Techmaturgy made a breakthrough in the field of intelligent steam automation. Their creation, the steam golem Blitzcrank, was developed to exercise judgment on-the-fly in order to assist with Zaun's hazardous waste reclamation process, since so often the conditions did not allow for human supervision. However, he soon began exhibiting unforeseen behaviors.
Over time, the scientists were able to identify a demonstrated learning process, and Blitzcrank fast became a celebrity. As is sadly often the case though, credit for the golem's creation was scooped up by another - Professor Stanwick Pididly - though most now know the truth. In the wake of the ensuing legal maelstrom, it became evident that neither party truly had the steam golem's best interests at heart, and Blitzcrank humbly petitioned for personal autonomy. Backed by overwhelming support from the public, it took the liberal Council of Zaun only a few weeks to declare Blitzcrank a fully-independent, sentient entity. A unique being, the golem left Zaun, distressed by the controversy and feeling there was no place he could fit in. His travels led him to the one location in Valoran where unique beings have a place - the League of Legends. Fortunately, he was easily able to adapt his design to suit the rigors he would face on the Fields of Justice.
Though Blitzcrank may batter anything that stands in his way, he really has a heart of gold...encased in a framework of iron...in a carapace of steel.
Source: The Game Website.