This project is an investigation into the theory of algebraic curves. We start by considering the basic definition and characteristics of an algebraic curve. We consider how an algebraic curve lies in a projective space and this leads on to studying the intersection of two curves. The properties of some simple curves and how they intersect is considered in more detail including the group structure of elliptic curves. We also investigate some results from complex analysis and subsequently use them to define Riemann surfaces and explain their connection with algebraic curves. This leads to more advanced theories from complex function theory such as integration on a curve. The topology of algebraic curves as subsets of C2 is also considered.