The classification of simple Lie groups consists of four infinite series – the classical Lie groups, and five exceptional Lie groups, called
On the level of Kac-Moody Lie algebras/Kac-Moody groups the E-series continues as
The following are references on the Lie algebras underlying exceptional Lie groups.
Surveys include
wikipedia, En
J. R. Faulkner, J. C. Ferrar, Exceptional Lie algebras and related algebraic and geometric structures, (pdf)
Geometric constructions of exceptional Lie algebras are discussed in
José Figueroa-O’Farrill, A geometric construction of the exceptional Lie algebras F4 and E8 (arXiv:0706.2829)
Andrei Moroianu, Uwe Semmelmann, Invariant four-forms and symmetric pairs (arXiv:1202.3407)
Cohomological properties are discussed in