Pablo Picasso was a pioneering Spanish artist born in 1881 who revolutionized painting, drawing, sculpture, and ceramics. He had a father who was also an artist and was Picasso's first teacher. Picasso is considered the most important artist of the 20th century and had several defining periods in his career including his Blue Period featuring sad themes, Rose Period with brighter colors, Cubist Period focusing on geometric shapes, and Surrealist Period using distorted shapes. During the Spanish Civil War, Picasso painted one of his most famous works called Guernica to reject the war and terror against civilians.