The evolution of fast rotating massive stars at low or zero metallicity

Rotation plays a key role in stellar evolution. Its inclusion in evolutionary codes has allowed to better reproduce many observed features such as the number ratio of red supergiants to blue supergiants, the surface abundance enrichments or the variations of the Wolf-Rayet stars popu- lations according to the metallicity. While at solar metallicity, or down to the metallicity of the Magellanic Clouds, the stellar evolution codes can be tested through numerous observational con- straints, this is no longer true when the metallicity becomes very low. It is however interesting to explore the predictions given at very low-metallicity by a code that has been successfully tested at higher metallicity. The aim of this thesis is to explore the effects of rotation on the evolution of the first generations of stars.