The mini-course will focus on the properties of the monodromies of algebraic families of curves defined over the complex numbers. One of the goal will be to prove the irreducibility of those representations for locally varying families (Shiga). If time permit we will see how to apply this to prove the geometric Shafarevich and Mordell conjecture. The material that will be developed along the lectures are - analytic structure of Teichmüller spaces - theory of Kleinian groups - Bers embedding - b-groups - Mumford compactness criterion - Imayoshi-Shiga finiteness theorem.