When did they start printing books?

The earliest known form of book printing began in China during the Tang Dynasty (618-907 AD) when paper was invented. Woodblock printing was practiced in China as early as the 6th century AD, but its use in book production became widespread in the 8th century AD. The oldest printed book still in existence is the Diamond Sutra, printed in China in 868 AD.

During the Song Dynasty (960-1279 AD), movable type printing was developed in China by Bi Sheng. However, movable type printing did not gain widespread use in China, as woodblock printing continued to be preferred.

In the mid-15th century, Johannes Gutenberg in Europe invented a more advanced system of movable type printing. This method employed a casting mold to accurately and quickly produce metal type pieces with movable parts. Books began to be produced on a wide scale in Europe as the printing press gained popularity.