The Muslims brought to India a new system of medicine, the Unani system—which, before the dawn of modern medicine, was universally recognized as the most advanced and scientific system for the treatment of diseases. During their hey-days, the countries of Iraq, Iran and Turkestan were the most important centers of the Unani system of medicine in the world, and it was there that its greatest exponents and practitioners were born during the medieval age. After the establishment of Muslim power in India, and encouraged by the generous patronage the Muslim rulers extended to men of learning and ability, a steady stream of outstanding masters of the system poured into the country for a period stretching over five hundred years. Due to the priceless services rendered by these worthy men and their pupils—their spirit of dedication and high proficiency—the Unani system touched its peak in India. The indigenous systems (Ayurveda) faded into insignificance before the Unani system. No city or town was left without a practitioner of the Unani school. This system was cheap, simple, and in harmony with the Indian climatic and temperamental conditions. So it spread in India very quickly and did a wonderful service to the people, composed as they were mainly of the poorer classes. The Indian physicians, by their contribution, lent further glory to it. During the declining phase of Muslim rule, Delhi and Lucknow were its two major strongholds and now India remains the only country where this system is still in vogue.