Movable type was invented in the Northern Song dynasty around the year 1041 by the commoner Bi Sheng. Bi Sheng's movable type was fired in porcelain. After his death, the ceramic movable-type passed onto his descendants. The next mention of movable type occurred in 1193 when a Southern Song chief counselor, Zhou Bida (周必大), attributed the movable-type method of printing to Shen Kuo. However Shen Kuo did not invent the movable type but credited it to Bi Sheng in his "Dream Pool Essays".