Where and when did Arabic numerals appear? How and when did they get to Europe and Russia?

Arabic numerals were invented in India in the 5th century, shortly before the advent of Islam. The Arabs adopted them in the 7th-8th centuries and spread them throughout the caliphate. At the end of the 10th century, Europeans borrowed these numbers from the Cordoba Caliphate, but they came into use only in the 15th century – in Florence. In Russia, these numbers appeared in the 17th century, and spread under Peter I.