Cubism
Well, I Know 3: The Rose Period (1904 - 1906 ), The Blue Period ( 1901 - 1904 ), and Cubism ( 1907 - 1920's )
The period of cubism continued until world war 1 (1914). It stopped after world war 1 because a author named John Golding, who is widely known for writing his book called the "cubism", stopped writing the past history and analysts (information) on cubism.
Cubism
There were thousands of companies during the start of the industrial period that were involved in production. Virtually ever company around produced one or more things so there is no good number as to how many actually existed at that time.
It grew over a period of time.
Yes, at the very start of Cubism.
Analytic cubism (1909-1912) Synthetic cubism (1912-1919)
He created stylistic periods all through his career. Best known are the Blue Period, Rose Period and Cubism (and there are three cubism periods).
The Blue period 1901-1904. Rose period 1904-1906. Cézanne Cubism 1908-1910 Analytical Cubism 1910-1912 Synthetic Cubism 1912-1914 Classical Period 1920-1922 From then on Picasso's art cannot easily be labelled.
Blue Period, Rose Period, Cubism, Classical. After 1922 his styles vary but have no particular name.
20th century
After his cubist period it is difficult to attribute Picasso to any movement. He was simply his own art movement.
Somewhat, but his works in Picasso's African Period were not truly cubist. They had elements, but cubism formally came about when he collaborated with Georges Braque.
Cubism
He changed styles during his whole career. Cubism was one of his early styles.
Picasso made cubist paintings 1908 - 1915.