During the high medieval period, the Islamic world was at its cultural peak, supplying information and ideas to Europe, via Al-Andalus, Sicily and the Crusader kingdoms in the Levant. These included Latin translations of the Greek Classics and of Arabic texts in astronomy, mathematics, science, and medicine. Translation of Arabic philosophical texts into Latin "led to the transformation of almost all philosophical disciplines in the medieval Latin world", with a particularly strong influence of Muslim philosophers being felt in natural philosophy, psychology and metaphysics. Other contributions included technological and scientific innovations via the Silk Road, including Chinese inventions such as paper and gunpowder.