Generating the plane Cremona group by involutions

I will discuss the following theorem: For any perfect field, the plane Cremona group is generated by involutions. I will explain how the decomposition of birational maps into Sarkisov links gives a generating set of the plane Cremona group. Then I will decompose these generators into involutions, among them are Geiser and Bertini involutions as well as reflections in an orthogonal group associated to a quadratic form. This is joint work with Stéphane Lamy.