During the Early Medieval Period, Jews rarely interacted with Christian Europe due to the increased levels of persecution. Jews of the period typically lived in the eastern part of the Byzantine Empire with the exception of those Jews that lived in Spain.
While Spain was under Muslim control, Jews were welcomed and even prospered. The Spanish Muslims and Jews shared a mutually beneficial relationship which was essential in promoting learning and science.
These relations changed drastically, however, when the Christians gained more territory and control. Once subject to Christian rule, many Jews were pressured to convert to Christianity or expelled to find a safe haven in a different country.
(History of Creativity, 368)
The Jews were very important members of the Spanish-Arab community. They played fundamental roles and were often considered to be the best physicians, philosophers, diplomats, bankers and slave-dealers. (Cultures of Spain - Carmen Pereira-Muro, 49)
Moses Maimonides is the "foremost intellectual figure of Medieval Judaism." A product of Cordoba, Spain, Maimonides became a world renowned philosopher, jurist and physician by a very tender age.
Maimonides is responsible for numerous writings and works with some of his earliest being produced at the age of 16. The first of his major works was his commentary on the Mishna, which he began at the age of 23. His commentary "clarified individual words and phrases, frequently citing relevant information in archaeology, theology, or science."
In addition to Maimonides' commentary on the Mishna, some of his major works include: Mishne Torah ("The Torah Reviewed"), Hilkhot ha-Yerushalmi ("Laws of Jerusalem"), Letter on Apostasy, and The Guide for the Perplexed. Maimonides contributions have left a universal influence in the fields of religion, philosophy, and medicine.
Information gathered from britannica.com