Institut de recherche sur les lois fondamentales de l'Univers

The first published spectrum of an AGN was   in 1908. In the 100 years since then we have made significant progress in understanding the phenomenology and physics of AGN. I will begin with a brief history of the development of our   understanding, highlighting the major breakthroughs.

I will then recap by describing our present "best" model and the so-called unified scheme. Finally, I   will discuss the most important current issues in the field such as; ejection of material from the nucleus and galactic feedback, the association of AGN with starformation and links between black  hole growth and galaxy evolution.