From 1912 to 1919 was Picasso's so called "Synthetic Cubism Period". During this time, he started to use collages in his paintings. His works from this time are called "papiers collés". He has spent his time during the First World War in Rome. In 1914, Picasso spent the whole summer in Avignon. In 1915, he started to paint realistic again. At the end of the same year, his wife Eva died. During the World War, he also worked as a designer for Sergey Diaghilev.