First published in 2002. The history of science is one of knowledge being passed from community to community over thousands of years, and this is the classic account of the most influential of these movements -how Hellenistic science passed to the Arabs where it took on a new life and led to the development of Arab astronomy and medicine which flourished in the courts of the Muslim world, later passing on to medieval Europe. Starting with the rise of Hellenism in Asia in the wake of the campaigns of Alexander the Great, O'Leary deals with the Greek legacy of science, philosophy, mathematics and medicine and follows it as it travels across the Near East propelled by religion, trade and conquest. Dealing in depth with Christianity as a Hellenizing force, the influence of the Nestorians and the Monophysites; Indian influences by land and sea and the rise of Buddhism, O'Leary then focuses on the development of science during the Baghdad Khalifate, the translation of Greek scientific material into Arabic, and the effect for all those interested in the history of medicine and science, and of historical geography as well as the history of the Arab world.