Refers to a Chinese dynastic culture, style, and period dating to 960 to 1127 CE. During the Northern Song period there was a new interest in antiquity and the beginnings of Chinese archaeology. Printing became more widespread and with it the publication of reference works. Imperial patronage was very noteworthy and influential at this time. For instance, the emperor Taizong (reigned 976-997) had an impressive painting and calligraphy collection and Huizong (reigned 1101-1125) commissioned catalogues of his own enormous collection. Huizong also established a school of painting as a branch of the Hanlin Painting Academy. Landscapes became more important with such notable artists as Fan Kuan, Juran, Guo Xi, Dong Yuan, and Li Cheng. The distinction between court painting and that of the Daoist literati became more pronounced. Northern Song ceramics are characterized by simple shapes, pure color, refined decoration, and technical perfection. Ding, Ru, Jun, and northern celadons made at Linru and Yaozhou were Northern Song wares patronized by the court. Sculpture became less symbolic and figures became more lifelike. Expensive defense and imperial extravagance led to a weakened dynasty; after incursions by the Jin, Huizong's successor moved south of the Huai River to establish the Southern Song dynasty.