This dissertation intends to show that the author of Mensagem and the generation of artists who contributed for literary magazine Orpheu s publication, intended to create a new portuguese poetic universe, in order to give birth to the country s literary modernity. In order to accomplish that, they used, broadened and transcended concepts taken from the french poet Charles Baudelaire. From such concepts definitions, their use s range isdefined by Baudelaire s and Pessoa s points of view, and are used to sketch the definition on modern artist and, from him, the difference between modern and modernism. Finally, it discuss the importance of both on the portuguese scenario, while examining the beginning of the century social-political-economic conditions in Portugal, critics reaction to the new aesthetics introduced in Orpheu and the groups poetic project, always highlighting Fernando Pessoa s leading role in critics and in codifying the movement s theoretical bases.