There have been many theories in the recent decades on the authorship of the works by William Shakespeare. Doubts have been cast on his authorship as well as on his life. All the theories that oppose the genuinity of the authorship of William Shakespeare are not sound, nor academic, nor in accordance with the historical facts. In this article I present the arguments on why it was William Shakespeare who indeed wrote his plays and noone else and that all other theories are just speculations and fiction. This article is writen upon a long period of studying on the works of Shakespeare, his life and style and in coherenwith the paramount authors on his life and works.