Korea and Japan sinicized because their ruling class were largely impressed by China's bureaucracy. The major influences China had on these countries were the spread of Confucianism, the spread of Buddhism, and the establishment of centralized governance. In the times of the Sui, Tang and Song dynasties (581–1279), China remained the world's largest economy and most technologically advanced society. Inventions such as gunpowder, woodblock printing and the magnetic compass were improved upon. China stood in contrast to other areas at the time as the imperial governments exhibited concentrated central authority instead of feudalism.