It is difficult to overstate the influence Pablo Picasso had upon the avant-garde art of this century. His exploration of Cubism, itself triggered by Cézanne's pioneering endeavours, could be said to have changed art forever. First his Analytical Cubism took apart the forms he studied and reduced them to their most elemental shapes. Then his Synthetic Cubism experimented in a "putting together" of shapes in cubistic patterns. Certainly no artist was more influenced by Picasso than was Fernand Léger. He was especially enthralled with Picasso's exciting Synthetic Cubism. Putting his own stamp upon it however, he moved beyond "cubes" and began using cylinders and tubes in the compositions of his work. Hence, he has been accused of inventing "Tubism".