Chevalley group of type E8

Definition
Let $$K$$ be a field.

The Chevalley group of type $$E_8$$ over $$K$$, denoted $$E_8(K)$$, is defined as the group corresponding to the Dynkin diagram:



For a prime power $$q$$, $$E_8(q)$$ is defined as the group $$E_8(\mathbb{F}_q)$$.