Algebra

When the barbarians invaded the citadels of Rome and Europe was plunged into the dark ages, the flame of knowledge was kept alive in the east.
One thousand years ago, in the House of Wisdom in Baghdad, scholars would gather from afar to discuss astronomy and mathematics. Scribes copied and translated the ancient texts, and it was through these that this knowledge returned to Europe once more. Many Greek classics are only known to us through these Arabic translations.
The Arabic scholars made important discoveries of their own. Their research gave such words as alcohol and alchemy.
It was here that Al-Khwarizmi devised a systematic way of manipulating numerical relationships between unknown quantities: a method he called al-jabr, or in modern English, algebra. This technique proved invaluable in commerce and eventually spread to Europe where several centuries later, Rene Descartes applied it to geometry, effectively uniting the realms of shape and number.
Behind Al-Khwarizmi’s innovation was a deeper idea: a specified set of rules determining each step in solving a problem – what we now call an algorithm.