Biography

Heimerdinger was born in Bandle City, the capital of Yordle Land. Yordle Land is the mountained off coastal strip on the southeast corner of Runeterra’s main continent where, unsurprisingly, most yordles live.
Yordles, for those that don’t know are a race of small animal/oompa-loompa style humanoids. They’re roughly 3 feet tall, enjoy socializing and pranks, excel at creating complex tools, and require constant socialization with other friendly individuals, preferably yordles.
Heimerdinger grew up in Bandle City, but quickly peaked his academic prowess. He acquired four doctorates before realizing that he was the smartest yordle in the entire city, and felt that he needed to move to continue his education.
He set his eyes on Piltover, the City of Progress, which is on the almost complete opposite side of the map. The city is world-known for having the best academies and scientists in the world, without being evil. It was a perfect fit for the good-natured Heimerdinger aspiring for challenge.
But, and this is interesting, Heimerdinger “knew he would never thrive away from his own kind,” so he recruited other like-minded Yordles to travel with him to Piltover and establish an academy there. Among them was Corki, the ship-flying, vehicle engineering yordle that is also a champion in the League. (He’s also one of the few champions to compete Heimerdinger’s claim on wackiest facial hair, if you ask me.)
In Piltover, Heimerdinger and crew established the Yordle Academy of Science and Progress to host their research and testing facilities. Despite its name, the academy welcomed all races into its ranks, although the core was initially yordles.Thanks to their amazing inventions and interactions with others, the institution quickly became one of the best techmaturgical institutions in the world.
Techma- what? Techmaturgical is a made-up word that basically describes an area of research and construction that combines technology and magic, usually by creating technology that can interact with or control magical elements. Almost all of Piltover is built on this technology, achieving a steampunk-style aesthetic.
An easy example is that Heimerdinger has no magical powers, but he built a device called the D.O.O.M. machine. The device is based in technology, science, but it’s capable of draining magical energy out of its environment. It’s science and magic working together.
Heimerdinger is not a bureaucrat, though. So while he’s still a leader of the academy (and insists on being present at the start of every year to welcome new students), he formed a secondary company with his friend Corki: Piltover Customs for side projects. Piltover Customs was built to give Corki and Heimer a place to focus specifically on researching techmaturgical vehicles.
At some point, Heimerdinger began experimenting on himself, which is rarely a good omen for one’s mental sanity in the future. He was successful in allowing himself to use a much bigger portion of his brain, but his procedure had the side-effect of massively increasing the size of his brain, disfiguring his head.
Even without the procedure, it’s likely that Heimerdinger was the smartest member of the league, and possibly in the entire world. But after his procedure, there’s absolutely no doubt.