Important Medieval events include the Battle of Tours, the Great Church Schism, the Black Death and the Magna Carta. All of these events played major roles, not only in shaping Medieval life, but also in shaping our current world history.
The Battle of Tours (732 AD), pitted Umayyad Muslims against Frankish Christians. The Umayyad army had just conquered modern-day Spain and was set to go into the heartland of Christian Europe. The Franks defeated them at Tours, possibly preventing the collapse of Europe and Christianity as world powers.
The Great Church Schism of 1054 saw the church split between east and west. The Eastern Christians within the Byzantine Empire refused to acknowledge the supreme power of the Pope and also differed on some religious beliefs. The split resulted in the western Roman Catholic Church under the Pope and the less centralized Eastern Orthodox Church.
The Black Death was a devastating plague that wrecked Europe in the 14th century. It claimed so many lives that it resulted in the collapse of the feudal system and a weakening faith in the Roman Catholic religion. This led to social renewal, the Renaissance and religious reformation in the aftermath.
The Magna Carta, issued in England by barons under King John's rule in 1215, was a document that challenged the absolute power of the king and gave certain rights to Englishmen, such as a right to a fair trial. It is the starting point for today's constitutional governments and bills of rights.