Al-Kindi (801 - 873)

Abu Yusuf ibn al-Kindi was a Muslim mathematician, physician, musician, and philosopher. He may be best known as the father of Islamic philosophy. Al-Kindi wrote several mathematical works covering arithmetic, geometry, and proportions. His four volume work entitled On the Use of the Indian Numerals which helped popularize the use of the Indian numerals in the Middle-East and West. In crypotography he used the frequency of the occurrence of letters to help break ciphers.

Stamps

Stamp	Description
	Iraq, gf, 1962 Scott: 303 A54
	Egypt, 20m, 1975 Scott: 998 A458