Noh is the classical theatre of Japan which was codified in the 14th century by the father and son actors Kan'ami and Zeami under the patronage of the Shogun (supreme military leader) Ashikaga Yoshimitsu. Under Yoshimitsu the Zen principles of restraint, understatement, economy of movement and frugality of expression became incorporated into the performance. By the early seventeenth century Noh had become an even more austere and formalised drama reserved almost exclusively for the military elite.