# Camille Jordan

**Marie Ennemond Camille Jordan**(January 5 1838 - January 22 1922) was a French mathematician, known both for his foundational work in group theory and for his influential

*Cours d'analyse*. He was born in Lyons and educated at the Ecole Polytechnique. He was an engineer by profession; later in life he taught at the Ecole Polytechnique and the College de France; where he had a reputation for eccentric choices of notation.

He is remembered now by name in a number of foundational results:

- the Jordan curve theorem, a topological result required in complex analysis;
- the Jordan normal form, and the Gauss-Jordan elimination method, in linear algebra;
- in mathematical analysis,
*Jordan content*is an area measure that predates measure theory; - in group theory the Jordan-Hölder theorem on composition series is a basic result.

*Traité des substitutions*, on permutation groups, was published in 1870.