  The goal of these lectures is to give an introduction to the study of the
fundamental group of a Klein surface. We start by reviewing the topological
classification of Klein surfaces and by explaining the relation with real
algebraic curves. Then we introduce the fundamental group of a Klein surface
and present its main basic properties. Finally, we study the variety of unitary
representations of this group and relate it to the representation variety of
the topological fundamental group of the underlying Riemann surface.
